Phineas and Ferb is one of the best and most thought out shows i know about. I mean how many shows do you know can have practically the exact same plotline every episode while still keeping it amazingly fresh. The music is just as amazing, although there may be some that arent as entertaining (very little), they still add to the show.
just a few of the amazing ones that i like
https://www.youtube.com/watch?v=vThpSTrHtlc
this ones special because it was in the episode that was an entire musical
https://www.youtube.com/watch?v=eAYeFMPaPjI
this one was in the movie and is a great battle scene where they use all their inventions at once
https://www.youtube.com/watch?v=avoMoHdNhXQ
one of my personal favourites
https://www.youtube.com/watch?v=7BPMZp5QYNE
a funny one just about a shoelace tip
https://www.youtube.com/watch?v=cMOdfwLNsSI
and finally the song that was so good it won awards.
These songs plus the hundreds of others all add to the show's creativness. I for one love Phineas and Ferb and think it is a great show.