Cactus Game Design Message Boards

I finally desided to get onto steam.  I will not be buying any games for quite a while (all my free money is going into cycling (and maybe a trip down south)) but I wouldn't mind playing demos.  I have already downloaded a couple of demos (Sactum 2 and Trackmania Stadium) and was wondering what are some good demos to try out?  I do like a variety of game so go ahead and list anything (though, please no horror bloody games).

Endless Space is a very fun strategy game, and I believe there is a demo for that (can't tell because I own it ).  It is also cheaper than some of the 'kings' of strategy, while being better (imo).

Otherwise, my suggestion as someone who has been on there 7.5 years, is make a wishlist by doing searches of game styles you like and checking the meta score, reviews, and descriptions.  With a wishlist, you can also have Steam send you an e-mail when it goes on sale, so you can save money.  Keep an eye on the featured games too, because you may find something for cheap that is also fun (like FTL: Faster Than Light, which is currently half-off at 5 bucks).