While it may not seem like it a good OP and/or ED is very important for an anime's popularity and success. A lot of the most memorable and loved anime are remembered partially for their catchy and addictive OPs and EDs. So what anime OPs and EDs stick with you as great?

I'm posting a few from this season that really stuck out for me.

Basquash OP - "nO limiT" by Eclipse

Basquash ED - "free" by Yu Yamada

Eden of the East OP - "Falling Down" by Oasis

K-ON ED - "Don't say 'lazy'" by Yōko Hikasa with Aki Toyosaki, Satomi Satō, Minako Kotobuki

If you can please post the artist and song name as well to make it easier for people to find more stuff on them if interested.

Lucky Star OP: this was just way too catchy, I had to listen to it every time I watched the show, while usually I just skip stuff over.

Spice and Wolf ED: Ringo Hiyori by ROCKY CHACK

Blade of the Immortal OP:Akai Usagi by Makura no Soushi

This is what happens when I limit myself to Cable and Youtube.

There are more but my browser's being a pansy and won't let me get more.

Hehe I knew Lucky Star and Haruhi wouldn't take long. He's some more. Some of these are pretty different (especially the 2nd one I'm posting).

Toradora! ED 1 - "Vanilla Salt" by Horie Yui

Busou Renkin ED 2 - "Itoshiki Sekai" by Aya Kagami

Turn A Gundam ED 2 - "Tsuki no Mayu" by Aki Okui

To Aru Majutsu no Index OP 1 - "PSI-missing" by Kawada Mami

Midori no Hibi OP:

Kannazuki no Miko OP:

Kannazuki no Miko ED:

Stellvia of the Universe OP:

Mai Hime OP:

Full Metal Panic OP:

Those Who Hunt Elves OP:

Scrapped Princess:

Outlaw Star OP:

Toradora OP "Pre-Parade"

History's Strongest Disciple Kenichi ED 3

Spice and Wolf OP - Tabi no Tochuu

Fullmetal Alchemist - "Ready Steady Go"

One Piece - "We Are"

Outlaw Star OP - "Through the Night"

This is about the point where the page is almost too laggy to bother loading thanks to youtube videos. Nice seeing this thread.

Gundam SEED OP1

Gundam SEED ED1

Gundam SEED Destiny OP1

Gundam SEED Destiny ED1

Code Geass OP1

I will post more later because some awesome OP/ED songs didn't fit in one post. =P

the first death note op ^