1. Firefly--the only one for which I have any real affection. The dialogue, the tone, the cast--it really clicked for me. Of course, I am aware that this one wasn't on long enough to really screw it up.
2. Buffy. Some interesting characters, but a bit too self-consciously cutesy at time. Not appointment viewing for me, at all, but there were a few episodes that I thought were well done.
3. Liked some of the later seasons, but didn't like the lead characters much. Fairly "meh" most of the time.
4. Dollhouse. Extremely uneven, and driven by, what I found to be, a thinly disguised prostitution festish that left me feeling like I needed to wash after every episode. The supporting cast were excellent, but the lead actress was so dreadful that I kept wishing she'd get killed off.
Hubby, however, worships Whedon, and insists we watch every damn episode of everything he does.