Celebrities have a reputation for being vain and self-centered - I know I've fallen for that stereotype before.

But of course celebrities are just like us. Some of them have even gone from rags to riches on their journey to stardom.

Each star finds their own way to give back to the less fortunate, including their favorite charities.

Plenty of celebrities choose Make-A-Wish, the charity that grants a special wish to sick or terminally ill children.

Meeting their favorite celebrity can mean the world to these children, and their families. A few generous stars went the extra mile while granting their wishes.

1. Tim McGraw

One of the most popular Make-A-Wish requests are concert tickets, to see a child's favorite musician in person.

But country singer Tim McGraw did one better for an 11-year-old girl named Taylor with skeletal deformation.

McGraw invited his lucky fan to join him on Good Morning America, before he gave a private 30-minute concert featuring all of Taylor's favorite songs.

"The joy that filled Taylor's eyes that day I will never forget," said her mom Kristi.

But McGraw has made time for his fans since then, including a touching moment with a Make-A-Wish fan at the Grammys last year.

2. Hulk Hogan

While the pro wrestler has retired from the spotlight, he was once one of the charity's most in-demand stars.

In fact, Hogan is one of the few public figures to grant over 200 wishes to deserving children.

One of the Hulkster's most memorable Make-A-Wish moments was in 1987, when he met eight-year-old Patrick Murray, who had liver cancer.

During his backstage meeting with Hogan, the pro wrestler told Murray, "Don't die on me, Patrick I love you to much."

Against all odds, Murray went into remission and survived another 12 years before his cancer returned.

3. Lady Gaga

The pop singer is one of the best-selling musicians of all time, with more than 27 million albums sold around the world.

But Gaga, whose real name is Stefani Germanotta, also lives with fibromyalgia, which causes chronic pain and fatigue.

When the singer canceled her 2013 tour because of her fybromyalgia symptoms, Kayleigh Gurzynski's family worried she would miss her chance to meet her idol.

The five-year-old girl had a terminal heart condition, and had traveled from Wisconsin to Chicago for Lady Gaga's concert.

But, as radio host Tony Waitekus shared, Gaga made the sacrifice for her sick fan:

"Even though Lady Gaga was not well enough to do the show tonight due to Doctors order (suffering from joint pain), Lady Gaga made it a point of still meeting Kayleigh!"

Sadly, Kayleigh died later that year, but we're sure she never forget this special moment.

4. Tim Tebow

The baseball player and former NFL star is known for being outspoken about his Christian faith.

But he also has a big heart, and loves to make time for children from Make-A-Wish.

Adam, a 16-year-old with a blood disorder and a passion for football, asked to meet Tebow as his wish.

The pair spent the day bonding, playing video games, and even had a game of catch together.

But Tebow also joined forces with Chip and Joanna Gaines from Fixer Upper for an extra special wish.

Tebow enlisted the design gurus to renovate a home for a pair of young boys with special needs, and you can tell by their smiling faces the surprise meant the world to them.

5. Mario Lopez

The Saved by the Bell star and host of the entertainment news show Extra pulled out all the stops for a Make-A-Wish kid.

Cayden, an 11-year-old with a brain tumor, asked to live life like a pop star for a day.

After a recording session, photo shoot, interviews, and a makeover, Cayden was invited to perform with Maroon 5.

He was escorted by a bodyguard past screaming "fans," and capped the day with an appearance on Extra with Lopez.

It was one of the charity's most complicated wishes, but Lopez pulled it off with style and left Cayden with plenty of happy memories.

6. Michael Jordan

The former NBA star hit the incredible 200-wish milestone in 2013, and hasn't slowed down since.

That's remarkable when you consider that plenty of the wish kids who ask to visit him weren't even born when he was in his prime.

Part of what keeps Jordan at the top of the list of most in-demand celebrities in the charity is his big heart and compassion.

Take Joseph Domingues, a 12-year-old battling leukemia. Domingues waited a year and a half to meet the basketball player, even passing up chances to speak with other NBA legends.

7. Miley Cyrus

While she doesn't brag about it, this former judge on The Voice has met with dozens of sick kids through Make-A-Wish.

Of course plenty of them are fans of her music, but they also grew up watching her on TV as Hannah Montana.

In fact, Cyrus was given a special reward from the charity on World Wish Day, and double-dipped by greeting eight wish kids at the same time.

"I get to meet so many people, and I don't think I've probably ever forgotten one of these kids," Cyrus said.

"I just want to do anything to make them smile."

Cyrus has treated her lucky fans to concerts, backstage meet and greets, and even trips to Universal Studios theme park.

8. John Cena

He may not look like a big softie, but this hulking pro wrestler has a heart of gold.

Cena is the reigning champ of celebrity Make-A-Wish appearances, with over 500 wishes granted for kids across America.

For his 500th wish, Cena took eight-year-old leukemia patient Rocco on the trip of his life.

The pair were interviewed on Good Morning America and Today before Rocco got to watch Cena wrestle from the front row.

But for Cena, every wish is just as important. The WWE superstar has personally donated 6 million airline miles to help families in need make their wishes come true.

For the record, Cena is sticking to his "never give up" motto, and says he plans to fulfill another 500 wishes.

9. The Cake Boss - Buddy Valastro

If you've ever watched Valastro's hit reality show Cake Boss, you know that he's famous for two things: making ginormous sculpture cakes, and being a family man with a big heart.

That made Valastro a surprisingly popular request among Make-A-Wish kids.

"Why would anyone want to come to me?" he remembered asking before his first visit in 2010.

Since then, Valastro has become one of the charity's busiest stars, and even featured some of his wish kids on an episode of Cake Boss.

"Now, I do it because I know it's great for the kids," Valastro said about his volunteer work.

"But let me tell you "“ it means the world to me to go and spend time with those children and these families and see that what I'm doing makes a difference."

10. Justin Bieber

Love him or hate him, the troubled pop star has done a lot of good work for the charity.

Bieber's connection to Make-A-Wish goes back to his teenage years, when he featured wish kids in the music video for his song "Pray."

He also made headlines when he became the first musician to grant more than 200 wishes.

Now, with more than 250 wishes granted, Bieber is still regularly making time for fans with severe medical conditions.

Nearly every stop on his Purpose world tour included exclusive meet-and-greets for local wish kids.

The singer also famously held a private concert for 20 wish kids in an L.A. bowling alley.

Many of Bieber's fans tell him that his music helps keep them strong during painful medical treatments.

Whether or not you're a "Belieber," it's hard to hold a grudge against the singer when he's doing so much good work.

11. Jeff Gordon

Now retired, Gordon made a name for himself as one of NASCAR's top racers.

But he also has a passion for charity work, and is one of Make-A-Wish's most requested celebrities.

Gordon rarely passes up a chance to make a wish kid smile, and has given a lot of young racing fans private tours of his garage.

Johnny, an 11-year-old lung transplant recipient, was even made Gordon's "honorary crew chief" before watching Gordon race live in the Coca Cola 600.

"I was just so happy for Johnny," his mother Ann wrote, "he loves Gordon and the experience is something he and I will never forget."

12. The Rock

Yes, it seems like pro wrestlers and Make-A-Wish are a match made in heaven.

The Rock, aka Dwayne Johnson, known for his massive muscles and his even bigger personality, has visited dozens of wish kids.

Whether he's treating them to behind-the-scenes looks at his latest Hollywood movie, or surprising them with pro wrestling gear, The Rock always knows how to make wish kids smile.

He famously surprised a trio of deserving kids with a joy ride in a Lamborghini while dressed in a Santa hat.

"My Make A Wish kid's (Murat, Maria & Emily) LOVE Lamborghinis and sports cars, so... I had one waiting for them so we can have some fun," he wrote on Instagram.

"They freaked out. Which is always the best part."

13. Beyonce

With fans all over the world, it's no surprise that the pop superstar is one of the most-demanded Make-A-Wish celebrities.

Over the years, she's treated a number of kids to front row tickets and backstage passes at her sold out shows.

One little girl with a painful skin condition was so happy to meet her favorite singer that she jumped out of her wheelchair to dance along with her.

A video of Beyonce sharing a duet with Taylon, a 12-year-old with an incurable bone cancer, also went viral in 2013.

The singer fought back tears as she shared the microphone with Taylon for a moving perfomance of "Survivor."

14. Robert Downey Jr.

Somehow, between all of his blockbuster movies, press tours, and time with his family at home, the Iron Man star fits in a lot of visits for sick kids.

In fact, Downey received an award from the charity in 2016 for his dedication to wish kids.

One of his first visits was with Cameron, a sick child who visited him on the set of The Avengers.

Cameron has since recovered, and thanked the actor for his kindness years earlier.

"My wish "“ which was my first and only wish "“ was to meet Robert Downey Jr.," he said.

"What I remember most about that day was how kind he was, and how he went above and beyond to make the day extraordinary for me and my family."

But Downey is still helping children today, and recently made 37 wish kids in Singapore "honorary Avengers" at a special ceremony.

15. Adam Sandler

The former SNL star and Hollywood funnyman has been making families laugh for decades, so it's no surprise plenty of children want to meet him.

One of Sandler's most memorable visits was with Tysen, a young boy with a genetic condition called Pfeiffer syndrome.

After touring Sandler's studio and meeting the comedian, Tysen was surprised with front row tickets to a L.A. Lakers basketball game.

But first, Sandler surprised Tysen with another celebrity, his co-star David Spade.

Sandler's generosity inspired Tysen to give back himself, and he's since raised more than $1 million for charities in his own community.

If you want to read about even more good deeds, this unique wedding story will stun you!

And for more stories of celebrities making a difference, read about these stars who celebrate their children with special needs!