For me, although LBT defines my childhood, some of the songs they sing are annoying at times, especially when they get stuck in your head
But here's a list of songs that have always gotten stuck in my head (which actually includes most of them):
Eggs

that's among my fave songs; you can probably tell why, judging by my avatar and sig :3
I agree, though - sometimes those songs can be annoying. Interesting since the songs that I find annoying I also love dearly, so it's a strange relationship I have :3
@Mumbling: Hah! I caught myself singing Very Important Creature at the top of my lungs today^^
I love that song, though, When You're On Your Own.