Really quick - you are FIVE in back of the leader?
Um SF has 7 wins, Tampa Bay and Kansas City have 3 wins. Um, 7 - 3 = 4, no?!? If SF wins and KC/TB win - you'll lose the tiebreaker by one game it looks like! So I don't think you can actually take TB or KC and have a chance.
I will now analyze the four teams left as if all DO give you a chance.
St Louis is so bad, you almost have to throw them out. If you really thought they could win, you wouldn't be worried about the guy in the lead as he'd get eliminated

HOWEVER, if you truly are not worried about the elimination risk, this could be the

move to end all

moves as nobody behind you could possibly move ahead of you and Mr. #1 will be out of the way if the Rams find a way to pull it off. Uh, though the presence of Ike Bruce for SF and the possible absence of Steven Jackson for the Rams really makes this a

move I'd be inclined to chicken out on.
Tampa Bay, 3 win factor aside, is the next one I would drop from consideration. While it's true they are playing better - Atlanta is actually playing for something in their minds. The Falcons have NEVER had two consecutive winning seasons and this is a rare chance for them to end that streak. They played the Jets really tough and won even though they were eliminated from contention. It's true that the Bucs are playing better, but one can argue that they won their Super Bowl last week as well.
Kansas City. I'm a little clouded by my 3-win note above. I do think there's a clear break from the other 2 teams mentioned above. Denver has a lot of things going against it. Suddenly they have no receivers at all. Heck, their game may not actually matter for their own playoff chances by the time kick-off occurs! KC has stronger in their last 3 games (though a Bengals fan I can tell you my Who Deys have a bit of a problem with playing down to the level of bad competiton). Charles has really broken out in a big way. The thing is - the Broncos beat them in KC by 31! Orton only threw for 180 yards in that game. Buckhalter and Moreno combined for 199. Cassel played bad enough to get yanked and Charles only went 18 for 56.
So that leaves....Detroit!?! It might be crazy, but especially if your choice is this team (for what looks like a chop) or St. Louis, I think these are your guys. It's really more anti-Bears than it is pro-Lions. Like Tampa, the Bears kinda had their Super Bowl last week by beating Minnesota and screwing up their bid for a playoff bye. The Bears defense isn't exactly, uh, stoudt, and this game could totally turn into a bit of a school-yard type of setting. They do have at least some modest weaponry with which to go at that shaky Bears defense as well.
Good luck - regardless!
-QG