Minami-ke

Seasons 1 and 2 (2007 and 'Okawari'):  C
Seasons 3 and 4 ('Okaeri' and 'Tadaima'):  B

Minami-ke ('the Minami family' or 'the Minami household') is a sitcom anime about three sisters and their friends, it's been around for a while and keeps getting more seasons, which is good, because the first couple were kinda weak.

So we have Haruka, the eldest, who's responsible, beautiful and competent but occasionally snaps and gets furious with her sisters or slips into self-indulgent laziness.  Then there's Kana, the hyperactive, impulsive and thoughtless middle sister, who despite her mountain of faults is friendly, silly, forgiving and likes everybody, so long as they're entertaining.  Finally we have Chiaki, the youngest, intelligent, diligent and serious, though clumsy, and absolutely adoring of Haruka and intolerant of Kana.

The series doesn't bother explaining where the girls' absent parents are, or where they get the money to finance their existence, or why they're time-locked at the ages they're at, which they also don't explain.  Also, every so often characters are able to have conversations about people sitting next to them without them noticing.

There's also a fair amount of gender confusion among the younger members of the cast, with one elementary school boy crossdressing so he can hang out with Haruka and a boyish girl who Chiaki adopts as her 'little brother'.

The first season starts with some kind of poor introductions, and the depth of the characters doesn't reach the fullness of things until well into the second season.  The first two seasons also suffer from poor animation and a bit too much fan service respectively.  The third and fourth seasons (and the OVAs) both very much come into their own, but even then, the series is never uproariously funny, just good for some giggles.

Overall, if you need a sitcom that actually has male characters and don't actually want or need a story, Minami-ke is the closest I've actually found to a true Simpsons-style timelocked family-type comedy (aside from Sazae-san, but that's another topic for another time).  If you want a show with action (beyond snowball fights), anything supernatural (besides tying up your little sister to use her as a talking good-weather charm) or drama (besides panicking that you broke your big sister's jewelry) Minami-ke doesn't have it.