Uncharted for me. I really like Mass Effect 2 but found 1 to be very rough around the edges and way overrated by the critics in general (classic scenario of overlooking a heap of clear flaws).
Uncharted DF has a fun, good story and solid mechanics all around. It's flaws were an over-reliance on combat in some sections and an over-abundance of the same foe to kill in droves, plus too obvious a split between shooting vs climbing sections. The character models and graphics were stellar with only some screen tear as an issue. Vehicles were solid although they did bork the jet-ski controls a bit.
Mass Effect has a good, deep story and world, but the mechanics I found average across the board. The combat was weak (actually, given the focus on TPS combat it was terrible next to DF and Gears both out around the same time), the levels rough around the edges (particularly the filler side mission levels) and the menu and item management was awful. Character models were good but the rest of the graphics were pretty average and rough around the edges.
Both franchises hit their stride with number 2 but for me DF was somewhat underrated vs its achievements on release and Mass Effect overrated and its flaws often ignored so I'm going with DF.
BTW the poll time seems short now. I was going to go with Gears after some mulling previously but the poll was gone before I could get back to it. SMaybe it was just the way the timing fell but the poll seemed to open then close very quickly.
Try to be reasonable... its easier than you think...
