Sharon in season two
Okay, so initially, Sharon's main reason for being on the show is because she was Chris' best friends wife. Sharon hated Chris, and as far as I cna tell by the few episodes I've seen (and what I've read online) Chris hated her as well (as opposed to mistakenly thinking of her as a friend).
Then in season two, Larry left, and Sharon was still a main character. Now, was there any big reason for Sharon to still be on the show? With Larry gone, Chris had no reason to visit her (though he did in Spewey and Me, in an effort to hide Spewey), and I doubt Sharon would have wanted to visit him. Was she a friend or relative to Gus or something?