Lego Star Wars: The Complete Saga is a great compilation title (and I've put more hours into it than any other 2007 game due to co-op) but Super Mario Galaxy is easily the best game of 2007.
Super Paper Mario is a great game. They changed the Paper Mario games massively, but at least the story and characters were still on point.
Uncharted is fun, but flawed. It's surpassed by 2, 3, and 4. It's probably better than Golden Abyss and The Lost Legacy, though.

I don't often vote for the Nintendo option but Mario Galaxy is the clear GotY here

Halo 3 easily.

Voting will be over in less than 3 hours. While first place is basically locked in, Halo 3 and Portal are tied for second place.

While there was a close contest for runner up, there was really no contest at all for the winner.  The 2007 Game of the Year is Super Mario Galaxy and the runner up is Portal.

This year I have played all the main contenders :D
I actually have to give it to COD 4. Bioshock comes close with its world design, atmosphere, story and interesting gameplay, but the simplicity and minimalist design of COD 4 just does it for me. A short but pretty much perfect campaign in my opinion. Also love Portal, which was a game changer. Halo 3 is a little overrated, I prefer CE, 2 and Reach. God of War 2 probably deserves more recognition.
Super Mario Galaxy is of course great, but people tend to forget that you have to put 4-5 hours into these modern Mario games before the levels get interesting and just a bit challenging.

It was a good year for gaming. Super Mario Galaxy and BioShock are very close in my ranking, with Halo 3 in third place. I'd probably have to give the edge to Super Mario Galaxy for the #1 spot, but only barely. The gameplay was overall more fun, and as I weigh things most heavily on gameplay, that's just enough to give it the edge, though BioShock had some solid gameplay of its own and one of the most engrossing game worlds ever.

Halo enough said