Clannad opening!
Shounen Heart by Home made kazoku - Eureka 7
Most all of the Bleach openings but the new one sucks.
Gundam Seed's second opening - Pride (I haven't seen Gundam though.)
[quote name='TheHundreds']Can't Believe None Of You Guys Haven't Mentioned The 2nd Naruto [not shippuden] OP By Asian Kung-Fu Generation.[/QUOTE]
Yes! and Haruka Kanata, Naruto's second opening by Asian Kung-fu generation.