Cheat sheet to the Week 1 games:
Atari 2010 Bundle - $64.95: Totally not worth it, too much fat for very little meat.
King's Bounty Gold - $14.95: Great game, but Armored Princess is better than the original in every way. I'd really recommend just getting AP.
Neverwinter Nights 2 Gold - $14.95: Vanilla NWN2 is mediocre, but Mask of the Betrayer is one of the greatest PC RPGs in the last decade. Get it if you like RPGs other than Oblivion.
Rollercoaster Tycoon 2 Pack - $4.95: It's Rollercoaster Tycoon. If you're reading this thread, you've probably played some iteration of RCT. RCT2 is more of the same. Not bad for $5, but I very much doubt you'd play it for long.
Call of Cthulhu: Dark Corners of the Earth - $4.95: Avoid unless you like the Cthulhu mythos. Poorly designed in many places -- one of the most notorious incidences is running through a hotel attempting to escape some horror, only to find the majority of the doors are locked and dead-ends. Extremely frustrating in a Dragon's Lair kind of way. Still, aside from Eternal Darkness, this is the closest you'll get to a legit Cthulhu game.
Dark Void - $14.95: Avoid. Not worth your time, let alone your money.
Battlestations: Pacific - $17.95: Interesting game, essentially you direct forces like a tactical RTS but have the ability to take over certain units at any time and take a personal, hands-on role in battle. It's not worth $18 though.
Elven Legacy Complete Edition - $19.95: Recommended if you like Advance Wars type of games. Downside is that some missions can be almost like puzzle games, with very little room for error or creativity. An amazing amount of gameplay for your buck, though.
DCS: Blackshark - $14.95: Only one I've not played. deouble9s notes:
In [flight sim] communities you'll find most people singing its praises as being a super realistic helo sim.
Fallout 3 - $14.95: Fantastic game -- but save your money for the GOTY edition that includes all five pieces of DLC, three of which are good to awesome, two of which are boring to mediocre.
Gothic 3 - $4.95: If you've played Gothic and/or Gothic 2, you'll find Gothic 3 to be much more user-friendly but... lacking in something that the first two had. Repetitive quests, less interesting world, some other problems. That being said, I played at release and apparently there is a giganto player-made overhaul mod that really makes the game great. If it weren't for the fact that I have Risen, (essentially Gothic 4), in my backlog, I might grab this. If you can install the player overhaul on the D2D version, then it's worth the $5 risk for fans and new players alike.