Mahoraba ~Heartful Days~ is a fairly sit-com like series. A number of fairly weird people living in an apartment building. It fits the genre more than adequately and doesn't often have a continuous storyline excepting two storylines that are about 3 or 4 eps each.

Ebichu (Ebichu: The Housekeeping Hamster): If you can find this old series, badly animated, very perverted, but very funny. The funniest anime I've ever seen. (and I've seen a LOT)

Akahori Gedou Hour Rabuge: This series almost makes no sense, never has a story that exceeds a single eps. Really funny (for the most part, some sad pieces of eps too), the only problem is the group subbing it is incredibly slow. Only 5 eps out so far.

Pani Poni Dash: Another really funny series, but you basically need to be an otaku, or have a similarly huge amount of series under your belt to understand almost anything. Game references, 70 and 80's anime references, recent references, references to series running in the same season as this show, historical references, movie references (Japanese and American), you name it, there is a part of PPD that refers to it.

Come to think of it, PPD covers the Japanese equivalent to Family Guy. With all the pop culture references and television/movie references that make Family Guy as funny as it is. The only problem is, like I said above, you'd need to be as similarly emmersed in Japanese pop culture history for PPD as you do in American pop culture to get all the jokes in Family Guy.

OFF TOPIC EDIT: Hah. I just noticed I made 666 posts.

Now I have to make this pun. Ebichu is devishly funny.