Favorite opening or ending theme songs?

Does anybody have a favorite opening or ending theme songs?
Mine are.......
FMA: 1st ending - Kesenai Tsumi (in english - Inerasable Sin)
2nd opening - Ready Steady Go
4th opening - Rewite
Bleach: 1st opening - Asterisk
1st ending - Life is like a boat
2nd ending - Thank You!
3rd ending - Houkiboshi (english- Comet)
Eureka 7 : 3rd ending - Tip Taps Tip
2nd ending - Fly Away
4th opening - Sakura

Most of the theme songs I like because the songs have a really good beat to them, and it does match to mood of the anime you're watching.
And that's what songs I can remember now. ;)

1st Opening- What Up People? Maximum the Hormone (Death Note season 2)
1st Ending- My Will by Dream (Inuyasha 1st season)

I like most of the Inu Yasha theme songs, but I love the 1st opening song- Change the world.

Hmmm...my most favorite theme song from an anime will have to be the opening of Ghost In Shell: Stand Alone Complex. The song is called Inner Universe by Origa, and I think it's really pretty, because of the vocals and the words in the lyrics! The song also really fits with the whole series, as well. It's heart-touching, and I know how to sing to it! So, yeah. ^^

My favorite anime openings is
COLORS By: Flow-Code GEASS
Alumina By: Nightmare-Death Note
What's Up People By: Maximum The Hormone-Death Note
Futatsu No Kodou To Akai Tsumi By: ON OFF- Vampire Knight
ALONES By: Aqua Timez- Bleach 6th Opening
Asterisk By: ORANGE RANGE- Bleach 1st Opening

Well, this is a tough one, as many of the animes i like are older than the ones which are popular now.

Based on that logic i guess I'd have to go with the English opening of Yu Yu Hakusho. The pop style opening was.....intriguing to me, as I liked how the song contrasted with the anime itself.

It certainly drew me in, as i never really knew what to expect in the episode.

Please give reasoning behind your choices people. Lists alone will get the thread closed.

let me be with you-chobits
19sai-xxxholic
ohayou-hunter x hunter
and loop-tsubasa chronicles