Paranoia Agent's opening:

http://youtube.com/watch?v=-anabfAg06U

Yu Yu Hakusho's opening (Hohoemi no Bakudan, "Smile Bomb"):

http://youtube.com/watch?v=WGMUt7zmgGA (first version)

http://youtube.com/watch?v=hxR8iYiJFWM (second version)

http://youtube.com/watch?v=hxR8iYiJFWM (third version)

YYH's first closing, Homework ga Owaranai ("The Homework that Never Ends"), English:

http://youtube.com/watch?v=nv6Bm8wuybk

Second ending, Sayonara Bye Bye:

http://youtube.com/watch?v=DmgtHP_-AJE
Edit: Curse you, black orb.

Third Ending, Unbalanced Kiss:

http://youtube.com/watch?v=fOWQdjftp04

Fourth ending, which I don't remember the name of...:

http://youtube.com/watch?v=QZvlompYHoA

Fifth ending, Daydream Generation:

http://youtube.com/watch?v=fOWQdjftp04

These are all the TV cut versions. The full versions are of course 100 times hotter.

This reminds me that I need to get to watching those episodes of Death Note.