No.1 singles.

I'm not exactly sure about what it means by famous work cause loads of their albums are popular. I think it means their top music songs that've topped the charts. Here are their No.1 singles:

• 5 colours in her hair 
• Obviously 
• All about you / You've got a friend
• I'll Be OK
• Please Please / Don't stop me now(cover)
• Stargirl
• Baby's coming back / Transylvania 

5 colours in her hair is their debut single, it was their first No.1, written by Tom Fletcher, Danny Jones and Busted member, James Bourne. It stayed at the top for two weeks.Overall it spent 12 weeks in the charts. It is one of Mcfly's most known songs.

Obviously is also another popular song Mcfly are known for. It was written by Tom Fletcher who was inspired by his childhood sweetheart/now wife, Giovanna Falcone. 

All about you/You've got a friend was the official 2005 Comic Relief single. You've got a friend was shot when Mcfly visited Uganda. It shows Mcfly teaching them to sing, perform to them and playing with them, the Mcfly vocals in the last chorus was removed and replaced the chorus sung by the children. All about you had many different celebrities starring in it some including Dermot O'Leary, Fearne Cotton, Davina McCall, Graham Norton etc. Tom Fletcher wrote it about his childhoodsweetheart/now wife Giovanna Falcone. All profits were donated to Comic relief.

I'll Be OK is not as known as the other songs however it is renowned for selling more copies than 5 Colours in her hair. It is from their second album Room on the 3rd floor. 

Please Please/ Don't stop me now were released together as one single. However Don't stop me now is the cover of Queen's song. Mcfly's version was the official 2006 comic relief song.

Stargirl was inspired by Tom Fletcher's dream about him falling in love with an alien lady. It was originally called 'Good Night' however the band felt like it didn't fit in with the lyrics. In 2009, the song was played in space to wake up the astronauts, after Tom started up a campaign on twitter asking NASA to play the song in space. Since the start of 2010, Stargirl is played every Friday morning on BBC radio 1 on The Chris Moyles Show in a feature called 'McflyDay'

Baby's coming back/Transylvania was one of the first singles in history to reach No1 on downloads alone. Baby's coming back is the cover of the 1991 Jellyfish song. Transylvania is based on the story of Anne Boleyn  who is played by Dougie Poynter.