[ThomasJennings]

I did use the search bar, but I couldn't find a similar thread, so here goes:
What are your favourite anime opening(s) and ending(s), and why are they your favourite?

My Favourite Opening
Ghost In The Shell: SAC 2nd GIG (Rise)
http://www.youtube.com/v/dxD_Y6ax95Q&hl=en_GB
I love the song, the images fit really well and it more than makes up for the mediocre opening in the first series of SAC.

My Favourite Ending
K-On! (Don't say lazy)
http://www.youtube.com/v/igEKaCJhtk0&hl=en_GB
I can't really explain this one, I just really enjoy it :)

[The-Ville]

My all time favorites so far

OP: Elfen Lied

ED: Umineko No Naku Koro Ni

[nipple]

oh noes, not again... we have a bunch of these threads

[ThomasJennings]

Really? I tried searching... I'm sorry :( Won't happen again I promise

[tapirs!?]

I love the Elfen Lied op:
http://www.youtube.com/watch?v=33XHKwJ3d3M

I love the Tenjou Tengen op:
http://www.youtube.com/watch?v=4YUWD4BZ81Y

I love the Air op:
http://www.youtube.com/watch?v=2KKxFlWJh6M

I love the Death Note op:
http://www.youtube.com/watch?v=wdEE8t-4P8o
http://www.youtube.com/watch?v=tY2RWg44CUQ

I love the Lucky Star op:
http://www.youtube.com/watch?v=ViEH57xQu1c

I love Souten Kouro op (haven't watched the anime, but the op is awesome xD):
http://www.youtube.com/watch?v=dP6u6qRSqjo

I love the Death Note ed:
http://www.youtube.com/watch?v=pFq5EbcQTps

I love the Jigoku Shoujo (2nd season) ed:
http://www.youtube.com/watch?v=1U3I-f7paWY

I love the Chobits ed:
http://www.youtube.com/watch?v=VjE9T6FXk8A

all such lovely songs n_n

[Jasonbobdude]

Nice... I haven't watched K-On, but the spontaneous combustion at the end was intriguing.

My favorites would have to be:

OP: Code Geass (Hitomi no Tsubasa)
http://www.youtube.com/watch?v=RTAbWWfNFy0
Only used for two episodes... But I guess that kept it special.

ED: Gurren Lagann (Minna no Pisu)
http://www.youtube.com/watch?v=_kw7B6eLvDU

[Tazuto]

just, too, many, favorites X-x *splodes*

[scarmullet]

I like the second death note opening

Evangelion

Chobits

Azumanga Daioh

Haruhi Suzumiya

Trigun

[Noznin]

Not sure why, but i always was fond of the sorcerer hunters opening and closing.
Opening
http://www.youtube.com/watch?v=zOJDLZ_XoaU&NR=1
Closing
http://www.youtube.com/watch?v=FuBiFh8_v18&feature=related