"Ben" is easily the most unlikeable character on the show so far. He's *supposed* to be likeable, but he's not. I couldn't wait until he was killed (and I'm not spoiling anything anybody couldn't clearly coming by his 2nd or 3rd episode).
I think Marty is moderately likeable; Ruth more so. I don't know why people have found Wendy to be so great, or found Laura Linney's portrayal of her to be so good. I don't think her acting has been very good, frankly. Bateman can get away with short lines of mumbling because that's all his character is given after season 1. But we're supposed to be buying into Wendy as this fascinatingly complex character, but it's a pretty one-note performance that Linney gives it.
And yeah... Ben. The exhiliration with which I was hoping he'd be slaughtered for being such a dumbf**k was palpable. But Season 3 couldn't even give me good visuals on that. We were actually supposed to be sad about it. It might have been more sad if he had been less of a dumbf**k. When you've got a show that established itself as very willing to pile up a body count on characters that you get to know, it becomes harder for the show to get a response from the viewer when it happens.