Legal downloadable crap here

Because all the best stuff comes for free, right? Until agents bust you for piracy, stealing, etc. or something.

So yeah, post anything that can be downloaded LEGALLY and played onto your computer for only a bit of space on your hard drive. And give a description of the games you post in case someone's never happened to have played it.

SkiFree - take control of a skiier with your mouse and veer him down a mountain. Take one of three challenges at the start and get the highest score. And watch out for the Abominable Snowman at 2000 meters.

Chip's Challenge - play as a kid named Chip and navigate your way through puzzles to get laid by Melinda or something. So I lied about the second part. But it's for the mind.
http://takegame.com/arcade/htm/chipschallenge.htm

Sumotori Dreams - control a drunken robot as you wrestle another drunken robot to the ground. First to 5 rounds wins. And see if you can find the sandbox mode from the main menu.
http://www.fun-motion.com/physics-games/sumotori-dreams/

http://kayin.pyoko.org/iwbtg/downloads.php

I wanna Be the Guy. It's the ultimate challenge in terms of platformers. If you beat it, you're a God. Good luck though.

It's a side scrolling platformer and every pixel has the potential to kill you and end the last 10 minutes of your work.

In before rapidshit link to a pay game.

http://cavestory.org/downloads_1.php

cavestory, it's a great game. An instant sidescroller classic. you can even download programs to edit it. I have started making it NG themed but I barely ever work on it.
Check out the website if you're interested there's lots of info on the game.