Delete :

-Tengen Toppa(overrated "best anime" please are you kidding shit),

-Death Note (manga superior to this shite)

Sayonara Zetsubou Sensei both seasons (first eps cool then it becomes lame,boring,repetitive)

-Ghost in the shell 2nd Gig (NOT FIRST: Laughing man fucking pwnz and the 1st gig is awesome, second gig sucks ass and really boring uninteresting episiodic shit) Keep first Ghost movie,delete second.

About the others, i'm sorry but i still need to check out pani poni dashe etc etc. Others i know ofc like Samurai Champloo etc etc but are too badass to delete.

You should get yourself some empty dvd's(verbatim) and burn most releases that you think won't get better in quality (like Ghost in the shell 1st gig =not HD release..so burn away)

goodluck!