What I've Been Playing Lately

I've been focusing mostly on indie games.  I bought the Potato Sack and a couple of other Steam indie packs over the last couple of months, and have been working my way through some of those games.  The quality is obviously a bit more uneven than you'd expect when a game comes from a big studio, but some of the winners here are really excellent and can be found for almost nothing.  Quick reviews below: 
Cogs - This is basically a series of moving block puzzle, where you have to move blocks around in order to connect pipes and gears in order to make a variety of machines function.  It's basically the same thing over and over again, but there are a wide variety of challenges and a couple of different modes (including time and number of moves challenges).  While I generally think moving block puzzles are some of the most annoying parts of adventure games, they really work here.  The game has a style that is really appealing, and the game is really well done.  The music and sounds are perfect for the game, too.  Very relaxing to play after a long day.
AaAaAA!!! - A Reckless Disregard for Gravity - This is basically a first person game where you jump off buildings in a bizarre, futuristic world, and try to rack up points by doing stunts, tagging buildings, and breaking score plates.  It's entertaining for a little while, but the gameplay is pretty repetitive.  The game has an engaging humor to it, though, and the concept of just plunging straight down is fairly unique.  It would have helped to have a greater variety of achievements.  Right now I think there are only six, and a few are pretty easy to get while two will take dozens of hours to get anywhere near.  Given the impressive number of levels in the game, that would have been an encouragement to keep playing. 
Defense Grid: The Awakening - This may be the big winner of all the games I've been playing lately.  This is a pretty simple tower defense game, but it gives you a wide variety of towers to choose from (as well as levels of upgrades for each), and allows you to shape the path of waves of aliens.  Both of these contribute to a pretty entertaining game.  Each level feels a bit like a puzzle that has to be solved.  There is a lot of content here; quite a few levels, and each level often has multiple challenges and different awards based on performance.  So far I've put in over 40 hours and I'm still playing. 
Jamestown - Well made game, a throwback topdown shooter in the vein of Raptor, Tyrian and 1942.  The game is pretty short (I think there are only five levels, plus some challenges) and the gameplay is a little unorthodox (the Vaunt ability takes some effort to get used to), but the graphics and gameplay are smooth, the soundtrack is good, and the game just feels right.  Also, the story is just a bizarre combination of historical characters in a futuristic world.  As far as I can tell, this is never really explained.  The game may be best played with other players, but it doesn't appear that this is supported over the Internet (which is a pretty big drawback). 
Rush - Much better than the other game from this same developer, Toki Tori.  In this game you must guide blocks from the entrance of the puzzles to the end.  The blocks start out going one direction, and can change direction if they run into walls or if you place tokens on the ground.  The game just works for me.  I had plenty of "a-ha" moments playing this game, and seeing the blocks complete the puzzle can be as satisfying to watch as the cards being taken off the screen after successfully completing a game of Free Cell.
Toki Tori - In my opinion, not nearly as good a puzzler as Rush.  In Toki Tori, you control a chicken trying to solve puzzles in a 2d platform world.  You can use bridges, teleportation, and an ice cannon.  I wasn't able to get into it.  Frankly, it's pretty boring.
Zombie Driver - Made it through the story mode of this game recently.  It's kind of like an old school GTA clone, except with simpler missions and a city filled with zombies.  The graphics are decent, although you view the world from a high enough perspective that it doesn't need to be all that detailed.  The voice acting is terrible, but that may have been intentional to try to spoof a bad zombie movie.  There are several gameplay modes outside of the story mode that may keep you entertained, but I don't expect to get much more than 5 hours of entertainment out of this one.