Yesterday, I stumbled across a pair of independent games. They're multi-platform (windows/linux/mac), pretty cheap ($20ish), have playable demos, and have no DRM. The main reason I tried them was out of support, but I think they're good enough to buy. I may also crack them, if the full game is included, just for the fun/challenge (in addition to buying, of course).
World of GooWorld of Goo is a goofy little game with cheerful music and such. In it, build structures to get to a goal. There was a similar game online with 9 levels or so that we talked about at some point, but in this, even the demo has 10 or more levels (I haven't beaten it yet). Each level has a goal, and also has an "OCD goal" (which, obviously, is much more difficult).
My first reaction was, "this is dumb", but a half hour later, my reaction was, "wow, I'm still playing this and I'm having fun!"
The Penumbra SeriesPenumbra is a horror/puzzle game. It uses a physics engine for its puzzles which feels pretty smooth, in my opinion, not that I've played a game with a physics engine before. The graphics are a bit much for my poor laptop, but when I tune them down it isn't so bad.
My biggest complaint is that the demo is fairly short. But it has an awesome ending, so I can't really complain.
<edit> bought the Penumbra series ($20, why not?). I forgot to note also, Penumbra is very much Lovecraftian, which is cool. Besides the plot and feeling, the main character is named Philip and his father is Howard (HP Lovecraft = Howard Phillips Lovecraft). I doubt that's a coincidence.