Minecraft for me is a game where I play only it for like a month, and then get really bored and don't play at all for three months. That being said, my heyday was back around the Halloween update. I started permanently losing interest when they started adding more RPG elements and that terrible ending. It's still fun to fire it up now and again to see what's been added, though.
Funny, that's basically what happened with me. Same time frame, even. I love love LOVE the whole idea behind the game. What I don't like is how it's evolved. Not only is it really focused on the creative aspect (which I find a little empty and pointless, since I could just go create something "real" with the same amount of effort), it's also kinda become a huge blob of content, rather than having complex gameplay emerge out of a few deep concepts or mechanics. It's a personal complaint, but it keeps me from fully enjoying the game, even with the endless exploration and survival elements.
I found Terarria more fun, although it got boring after awhile as well.