I love Dollhouse. It's one of the smartest, deepest sci-fi shows I've ever watched. It explores themes of identity, memory, free will, gender, and the very essence of humanity, while keeping you entertained with lots of awesome spy-fi geekery.
However, the show has some significant flaws: The first 5 episodes are mediocre at best, but since the show is heavily serialized, you can't really skip them. Eliza Dushku doesn't have quite the range or the presence to fully convince as the main character. The show never quite looks or feels as sharp as it should, especially compared to "Alias" or "Fringe". As it nears its endgame, Dollhouse reveals a major plot twist that barely makes sense on a plot level and certainly doesn't make any sense on an emotional level.
Despite all those flaws, Dollhouse is still a great show if you bring just a little good-will and patience. Dushku's shortcomings as an actress are actually balanced out by a truly fantastic supporting cast (Dichen Lachman, Enver Gjokaj, Olivia Williams, Amy Acker, Summer Glau, Tahmoh Penikett, Alan Tudyk etc...)
In a way, Dollhouse has similarities to spy-fi shows like "Alias" and "Nikita", bit it has much more on it's mind. It explores some seriously deep issues instead of being just mindless entertainment. I would compare the show most to "Fringe", "Orphan Black", and the old 60es cult series "The Prisoner". I recommend Dollhouse to anybody with a taste for cerebral sci-fi.