I love real cheesecake, so I've tried several vendors cheesecakes. I have to say that as far as plain cheesecake flavor goes, the only one I like is Ms T's. Hers is wonderful. Tastes just like eating spoonfuls of cheesecake filling.
The butterscotch caramel cheesecake is really tasty as well, but I think I still prefer the good old plain one best.