Also a placeholder. I need to see two more films for certain, but I'll work a prelim list in a few days.
This I know (in no particular order):
Zodiac
No Country for Old Men
Ratatouille
The Assassination of Jesse James By The Coward Robert Ford
American Gangster
Those will probably be on there.
EDIT: Here we go, still missing a few films I have yet to see.
1) The Assassination of Jesse James by the Coward Robert Ford - not an easy choice to make, but this is the film I still linger over, the one I most want to see again. It's not even methodical...it's encompassing and lyrical to look at. Javier Bardem is going to win the Oscar (and that's OK), but Casey Affleck gives a monster performance here, across an exceptionally strong Jesse James. I also think it's the best score of the year.
2) Zodiac - Completely shunned at the end of the year, often for films that don't have an ounce of the staying power this film will show in times to come. Just a flawless deconstruction of criminal investigations and obsession. Fincher is one of the most gifted visualists in the history of film; here he takes a more direct, more traditional style (with a few trademark, brilliant flourishes that completely serve the storytelling) and matures into more than he has been.
3) Ratatouille - This was tough, as I still haven't listed No Country, but I think it'll get enough attention

I think Ratatouille was the most surprisingly great movie I have ever seen. It's Pixar, and I expect exceptional filmmaking from them. But this kicked it into another gear, and elevated their usual brilliance into something sublime. The animation was to die for, and at this point, we are discussing performances more than technology.
4) No Country for Old Men - This future best picture winner deserves it. I picked three films ahead of it, but I would argue none of them are
better films. This is the Coen brothers at the height of their powers, with some of the tightest, tautest filmmaking I've ever seen. Combine that with exceptional performances across the board, and an ending that requires some rumination and pays it off, and you have a very strong 2007.
5) American Gangster - Ridley Scott doing something he's never done before while doing what he always does. A period piece crime drama is common material for Hollywood, and has yielded some great films. Scott adds something exceptional to it, and audiences noted that, but critics seemed only mildly interested. Some directors simply have higher expectations and pay the price. This is not a great film, but it's a very, very good one. With some great scenes
6) There Will Be Blood - One of my most anticipated films, and the one I probably struggled the most with, including where to put it on this list. The filmmaking is exceptional, Daniel Day Lewis is a singular talent, and the themes are resonantly meaningful. It didn't click with me as much as I would have liked, but I'd wager some of that was me. The entire film rests on DDL's shoulders, and he carries it to the bitter end with swagger and raw intensity.
7) The Bourne Ultimatum - Basically a tighter version of the previous two films. It pays off the earlier films with a deft examination of the events leading up to Bourne's rebirth. The direction and editing are exceedingly polished, and Damon is a great center of gravity for the series. A very enjoyable summer film. I wish they could all be this good.
And this is where I'll stop ranking them and just list things I liked from other films. I tried to parse out the rest of my list, but they are interchangeable after this.
To caveat: I have not seen The Diving Bell and the Butterfly, Knocked Up, Gone Baby Gone, or Once.
Sunshine - was brilliant for two acts followed by a merely decent third act. But I loved the sense of science fiction, isolation and camaraderie this film established and ran with. If it ended strionger, this would have been an easy inclusion.
Juno - was excellent, carried by a great performance from Ellen Page. The screenplay is very good, though I found some parts of it a little too twee. Page nailed her part, however.
Enchanted - another film absolutely carried by it's lead. I now worship at the altar of Amy Adams, and the sky is the limit for her. This was a VERY difficult role to pull off, and she positively makes it work. Because, you know, it really shouldn't.
300 - for all of the snickering this thing gets now, it was gangbusters when it came out. It was gory, looked great, and reveled in being the anti-(anti-war) movie. I'm biased in that the events covered are among those I consider among the most important in human history - though I readily acknowledge, it went down almost nothing like this. Except at the most primal level. So while most now smirk at the tawdry nonsense, it echoed something magnificent with great action scenes...so I admit I liked it. I'd prefer Michael Mann to make Gates of Fire, but hey, you get what you get. Great action sequences, and a budget epic.