What is a good game involving coding?
How about RoboCode
You code your tank in Java and let it loose in the 'ring' with other coded tanks. People got pretty into coding strategy, targeting, etc. IBM sponsored it and came up with some nice introductory programming tutorials to get you started.
Here's a great article to get the feel for it:
Rock 'em, sock 'em Robocode!
alt text http://sourceforge.net/dbimage.php?id=89605
Uplink isn't so much a coding game, but it is a great game that makes you feel like a hacker.
There's a whole bunch of "drag-and-drop" coding games, where you make a little thing (usually a robot) solve some puzzle by giving it a list of instructions. They're only vaguely similar to actual coding, but they are still pretty fun.
RoboZZle
The Codex of Alchemical Engineering
light-Bot