Well, I started a thread a while ago about wanting to give Tales Of Symphonia yet another chance. I decided I will, but haven't done so yet, because of other highly anticipated titles on the horizon, such as Mass Effect 2 and Bioshock 2.
An actual example I can give is Freedom Fighters. At first I really couldn't get the hang of it so I tossed it aside. I came back a year or so later and barely stopped playing until it was over. Great game.
Also, the first Dungeon Keeper. It came out when I had intensely been playing X-Com: Apocalypse for weeks. Anything that came out during that time would be sampled for about five minutes after which I decided it wasn't X-Com: Apocalypse and therefore sucked. When I burned out on X-Com I tried DK, and was blown away.