Black Omega said:This is an absolutely silly anime, which is part of the fun. And yes, they don't hunt them to kill them, but it's almost as bad.
For sheer silly, it's hard to beat Excel Saga.
Beating Excel Saga is difficult but a few series match it in silliness or weirdness.
Puni Puni Poemy is in the same vein as Excel (by the same director and using some of the same characters). It's even more hyper and demented. It even breaks the 4th wall more than Excel Saga (e.g. at one point, you see the camera crew filming the characters). Only one DVD though.
Furi Kuri (Fooly Cooly) is as weird, if not weirder, than Excel Saga, but Excel is funnier.
Ebichu the Housekeeping Hamster (think Hamtaro redone by Heavy Metal magazine) is the kind of sick funny series that will probably appeal to Excel fans. Despite the cute name and cute simple art, the series is raunchy and very violent. Ebichu is unlikely to ever be translated for the North American market because it's just too weird and adult-oriented. You can find a fansub if you look online.
Ranma 1/2 is silly and funny but far less weird than Excel Saga. The manga's even funnier in my opinion. Ranma's more in line with "typical" comedy anime.