i´ve seen so many but the ones i liked most were :
Golden Time
Bokura wa minna kawaisou
Kotonoha no niwa ( a movie )
Hidan no Aria
Furi kuri
Isuka Tenma no kuro usagi
Nagasarete Airantao
Angel Beats
Black Lagoon (all seasons)
Kami-sama no Memo-chou
Final Approach
Kyosougiga
and a lot more such as the "normal" shounen stuff like bleach/op/naruto