I guess if I would recommend an anime, I could say Denpa Onna to Seishun Otoko, it's a simple 12 episode anime with a extra 13th but I sure enjoyed it. I would also recommend Chunnibyou if I could add another one

You better add FLCL to that list!

I would love to see either a spin off of clannad or another season of Ichigo Mashimaro. Those were both really good shows.

angel beats
steinz gate
neon genesis evangelion

if you guys have any good ones i would love to hear suggestions XD

For the good anime that is short, imho i can add Puella Magi Madoka Magicka (Magica?)

to aru mujatsu no index....
guilty crown
code geass
un-go
tiger and bunny
death note
sword art online
fma brotherhood
spicexworlf
eden of the east

some of the 12 ep animes that get you emotional are good short if you keeep them like some very very long ones:l but yes lucky star and K-on must be longer! *the others i havnt seen dotn throw stuff at me!* :3