Yes, on several occasions.. The more recent ones I are:
Red Steel - Novel concept at the time, but the controls were pretty horrid and the single player got boring
The Conduit - Got close to beating it, but just got bored in the single player, and the game tended to make me nauseous
Mass Effect - Not really bad as much as I just couldn't nail the controls and the battle mechanics. Just didn't click for me.
RE5 - Bored me, and seemed too much like RE4, just in a new environment. Didn't play this one much.
Manhunt 2 - Somewhat sluggish controls and boring gameplay after the novelty of the finishing moves wore off ultimately deterred me from finishing it.