20 Here,
I've always liked a pretty wide variety of video games, first person shooters are fun and all but I've started to shy away from Call of Duty and it's clones, never really got into them too much in the first place, it was always small maps, and either you ran in circles or sat in one place waiting for people, neither of which I found fun, but then I started played Battlefield 2, where the maps were huge and you wouldn't run into someone every .2 seconds, and you could plan your steps ahead of time, I was also a big player of Diablo 2 and other various role playing games, I usually play in streaks of one or the other however, and fallout 3 (new vegas soon) is usually my transitioning game when I switch over from one to the other.
At the moment I'm playing Fallout 3,(New Vegas soon), (waiting on D3), Battlefield: Bad Company 2 which has decent sized maps and destructible environments, set down Mass Effect a while back which is another good rpg/fps you could look into, and recently tried out Bioshock 1 which was good but I've heard that Bioshock 2 doesn't really expand upon anything, and the new Bioshock coming out isn't related.
Puzzle games I find a bit boring but if they have other elements in them, say like (when I was younger) Sly Cooper or other adventure/puzzle games were fun, now it's more like God of War's puzzles or Dark Siders, Some of the puzzles are pretty easy, but until they release a decent Zelda remake They'll do.
Here's to hoping that Uncharted gets released on the 360 or PC because that games looks to be like a lot of fun. Hate exclusives :/ The Halo series is ok offline but online it's just pre-teens screaming at eachother and more small maps and circle running gameplay.
Anyways, sorry for the randomness and all but I thought I'd let ya know, also I think it's cool that you're still playing games into your 40's and I find it entertaining, not in a bad way mind you, that you're excited for a video game release.