I've been meaning to replay HL at some point, Junk. Hearing that it's still good makes me eager to do it soon.
I've been playing a lot of
Chime recently on XBLA. It's a puzzle game a bit like Tetris but instead of the blocks falling down from the top of the screen, you're placing them on a grid, connecting them together to both clear the shapes and cover the grid underneath. The aim is to cover the whole grid with cleared shapes but the game also has the Lumines line that comes across the screen and it really interacts with the music, 'playing' the blocks.
This probably makes no sense to read so i'll embed a trailer:
Got it? Good. I'm finding it quite compulsive, there's a nice mix of competing on leaderboards and enjoying the music (from Philip Glass, Paul Hartnoll, Moby, Markus Schulz and Fred Deakin) and it's become my chill out game after frantic 360 shooting. I'd recommend trying the demo, it's only 400 points and all the money goes to charity too.
Steam's weekend sale is
Toki Tori, a fun puzzle platformer starring a yellow penguin. Half price, £1.62.