I used to have the first Dues Ex but can't find it now. For me, I thought it was different in a good way. Haven't played any others since. I might look into this one.
DE: Invisible War (the second DE game) was also a good game, but a dumbed-down version of the original in respect to the RPG elements. Also I've never seen it run above 20fps on top-end hardware then (2004) and top-end hardware now.
I really want resistance 3. Maybe I'll give ES5 a shot. Over the summer maybe I'll try my hand at Oblivion one last time. And yeah, I gotta get around to mass effect sometime.