Mirror's Edge?
If we're talking more traditional FPS games, Crysis 2's movement feels essentially perfect. The speed seems pretty reasonable, the sprint feels fast without being unbalancingly fast, the slide feels both cool and relatively realistic, the drop animations (both with and without armor) give you cause to avoid just dropping down in front of someone from high up, add to realism, and look great, and the ledging is intuitive, stylish, and functional.
Half Life seems like a sad choice in 2011. It has great physics for a lot of things, but the movement physics are not a real highlight, especially compared to games that didn't come out seven years ago. Seven years is plenty of time for developers to take pretty much every good idea that was in Half Life 2's engine and improve on it. Surely the game still has a leg up in with some of its physics, but simpler, more routine things like movement physics have progressed since then.