Well ME has Trophies and Tomb Raider currently doesn't. So if that's a selling point and you want to rack up the Trophies, then ME is the way to go.

Get some other game like Resistance 2 or Valkyria Chronicles.

Mirror's Edge is terrible. Simple story, uninteresting characters, the levels are bland and uninspired. The game is very short and repetitive. Combat system is bad. The time trials aren't worth a look.

I got Tomb Raider Underworld a couple days ago. It's not the best game ever (thanks to a wild camera, and an outdated combat system), but I am REALLY enjoying it. Graphics (even though quality varies), controls, and atmosphere are top notch. The puzzles require some serious thought, but Lara will give you hints if you need them. And there's always the internet if you need a FAQ.

If you enjoyed Uncharted, but you want more adventure and less action, buy Underworld. If you really enjoyed Uncharted's combat, you may want to pass. I'm loving it, though.