Lizardball
This is a realistic baseball simulation in the mold of Strat-O-Matic and APBA, played with 10-sided dice (or anything that will generate random numbers from 1 to 1,000, such as a calculator or OSX Widget). At its basic level its very easy to play, although I've played around with varying levels of complexity. I tend to play it in bursts, so I'm not using updated, present-day teams, or else I'd post them here along with the game rules, and I don't really have time to do all the updates or normalize the formulae used to create players for the current season (especially since it's not clear how steroid testing will change the norms, and the system rates players based on three years of performance). I suppose if people are interested, I can convince one of my baseball fanatic former students to run the numbers and I'll post it here.