Two different types of game I know...
Anyone played both?

Ive played both,Gears wins hands down IMO,Gears 2 is much more epic,and has much more of a feeling to it,at some points in Gears i felt like i was in some Lord of The Rings wars,it was a great game.

Fallout 3 made me feel sick sometimes,seriously,the enviroments and etc gave me headachs,it was a good game,but the VAT system got boring half way thru,i mean,say u dont wana choose a part to shoot? Without choosing,the aiming system is pretty bad,i couldent aim and shoot and do damage as good as it wasnt sharp,not to mention,when u run out of ammo,and u got 1000 super mutants who all look exactly the same run at u is a *****

Gears 2 wins.

I'll have to wait for gears 2 to come out on PC before i answer that.

But i'd have to say gears simply because it has multiplayer and co-op play. Fallout 3 is great but if you don't like rpgs, well, you won't like it.

I know these 2 games will probably be competing for game of the year because of the huge hype they are getting. But the best game i have played this year is left 4 dead, it came out 3 days ago and thats all i have been playing, with a little bit of command and conquer 3.

Not played GOW2, but I'm playing through Fallout 3 at the moment and loving it. 6 hours straight yesterday, I hardly moved, just sat and played it.

How can you compare a Sandbox RPG to a Third Person Shooter? That's really just preference you're dealing with and in my case, my mood.