I don't know what you guys are talking about. I love how big the cast is, and Ann and Chris are used pretty well imo. I still find Chris's health-nut stuff really funny even if he's become a parody of himself, and he's the perfect foil to Ron. Ann is really just on the show to be Leslie's best friend, but I think this is important and is what gives Leslie that sympathetic quality Monga was talking about. Going back to my other two favorite comedies of the 00s, Michael Bluth and Scott don't have any friends at all. It makes them seem less human and understandable.
I guess if I thought they should "trim the fat" of the show, I would take Ann out, but I really don't think there's any reason for them to lose characters.
Oh I totally agree that Ann is a great foil/straight woman for Leslie. I just don't think she works particularly well with anybody else given how tenuously she's connected to most of them. The last 2-3 episodes she's been paired up with Ron and those stories have been superfluous. Leslie is already Ron's mentee/surrogate sister and April is already Future Girl Ron. There's no room at the inn. I really think they need to keep Ann in storage for when they need her in Leslie stories (and occasionally to have April shit on her) and just not use her besides that. Have her be more of a Donna and not the second female lead she's been the last 2 years.
Chris/Rob Lowe (don't know what to call him since the whole reason he's on the show is because he's Rob Lowe, star actor/ratings bait, and not Chris Traeger, integral character.) is just an odd case because there was never much expectation that he'd be on the show long, until he was. He would have played a big part as an antagonist had Leslie and Ben not broken up, until they did. Now he's just there banging Jerry's slutty daughter and taking up space.