Manga-wise, she's OK. She can seem annoying at moments such as protesting Gohan going to Namek or saying Gohan's education is more important than the Earth's future, but from her perspective as a mother trying to raise a child in such a bizarre world, it's somewhat understandable.
Anime-wise, Toei just exaggerated that tendency of her's with filler to make her an annoying bitch, with Super going down this route as well.
Pocket-God said:
Oh and a question, how different is she in the Japanese version/manga compared to the English anime?
Same annoying bitch in both, other than Japanese Chichi talking with below average grammar, though I'd probably say I find her Japanese voice more tolerable, particularly when Mayumi Sho voiced her (her voice in the original DB, the first 80 or so episodes of Z and the first 3 DBZ Movies).