I haven't seen a thread for this (atleast not recently). I guess this is the evil twin of OTM's Favorite Anime Openings Thread. I'll start! my favs are
1) Tobira no Mukou e - Hagaren
2) Tsuki no Ie - Outlaw Star
3) Shizuki - GTO
4) Yasahii Yoake - .hack//sign
5) Ride on Shooting Star - FLCL
6) Namida no Hurricane - Get Backers
7) Lithium Flower - GITS: Stand Alone Complex
8) Kimi Sae Ireba - Love Hina
9) Real Folk Blues - Cowboy Bebop
10) Fukai Mori - Inuyasha
...so what are your favorites??