Played a whole lot of the recent games, beyond ones already talked about a bunch like TIC, Lair of the Evildoer, and Platformance, there's a few other I really like (and a bunch of others that vary from crap to alright):
Them Blockzhttp://marketplace.xbox.com/en-US/Product/Them-Blockz/66acd000-77fe-1000-9115-d802585508a9, 80msp, a puzzle game where you have to bring colored blocks to specific tiles by having them stick to you. The problem being figuring out how you'll be able to maneuver around the levels with the extra blocks making you bigger. Really liked the concept and the minimalist art style, which comes off looking more like a design choice than a "I can't design anything decent" choice.
Block the Laserhttp://marketplace.xbox.com/en-US/Product/Block-the-Laser/66acd000-77fe-1000-9115-d802585508ae, 80msp, a puzzle game where you have to walk over buttons to arm/disarm lasers or rotate walls to clear a path to the exit while moving forward/left/right. Found it a lot more interesting than I thought I would, there's a decent progression of new elements introduced as you go along in the trial.
Kung Fu Fight!http://marketplace.xbox.com/en-US/Product/Kung-Fu-FIGHT/66acd000-77fe-1000-9115-d802585508ad, 80msp, an auto-running platformer with super retro graphics and a decent sense of humor. Has a good amount of polish and even in the trial there's a variety of enemies and hazards that require you to use pretty much every option at your disposal.
When Maidens Attack, 80msp, a platformer starring a maiden, chasing a very underclothed bearded man who stole her shoes after she chopped his clone in half for punching her in the face. Also a fairy made all the unicorns angry at you so you kill them all and take their hearts, even the baby unicorns. Yeah, that old chestnut. The actual game is fairly basic, you have a lightsaber attack and some magic you can aim with the right stick, and if you use the dash button you'll probably crash into something and lose half your health.
Shift It, 240msp, a block moving/matching puzzle game. It's a bit rough to look at, and there's not really anything unique about the concept, but there's decent puzzling to be found. Didn't really hold my interest enough for a purchase, since this is a really crowded genre and games that feel more original like UpBot Goes Up get my attention.
Poopocalypse, 80msp, a side scrolling poop bomber game. Nice graphics and presentation, but not really feeling the gameplay much. The flying controls feel awkward, and there's not really much in the way of variety, I mean, there's only so many ways you can poop on something....
Monster Escape, 80msp, a puzzle game where you place sets of blocks on the map to let you get to eggs. It seemed almost stupidly easy, and the monsters seem way larger than need be to the point where they're sorta in the way. Maybe it's more for young kids? High quality graphics, though.
The Angry Hand of God, 80msp, a destruction game. For a game about god smiting humans and destroying cities, it felt really slow and weak to me. Maybe I just didn't have the hang of it. Seems like I could have done a better job destroying the side scrolling city as a Rampage monster than as god!
Avatar Battle Bees, 80msp, these kind of dogfight flying combat games aren't really my thing, but this one seemed to be lacking a lot of the maneuverability other games in the genre have. Pretty nice art style, though.
Mad Blocker Arcade, 240msp, a match four falling block puzzle game that is apparently based on some earlier flash version. You don't rotate the blocks you can just switch their order in the horizontal line they are in. Not a whole lot of fun.
A Game About My Cat, 80msp, seemed really boring. Kinda cute graphics, but there's plenty of better side scrolling "trick" games on Xbox Indies (Pixel Boarders being the best).