I quite enjoyed Dollhouse, but that may have been enhanced by me watching it in a marathon over a couple of days on Netflix. I thought the concept was fascinating, and enjoyed the arc that spun as the show gathered speed. Echo was perhaps an iffy lead character, but there were plenty of other well drawn characters to pick up the slack.
I understand that the show was cut short, and a lot of the future storyline happened in a rush at the end of season two. Whilst that's a shame, I think the limited run ultimately helped the series. I could have seen the story twisting and turning in strange directions before receiving appropriate closure.