I’m in the mood for something really basic tonight, so could anyone recommend me a freeware (downloadable, Java applet or whatever) old-school shoot 'em up game? Lots of shooting to get to the next level, that’s all I ask.
Go here and shmup until your freaking brains explode.
I recommend Tumiki Fighters or PARSEC47. Particularly PARSEC47. Hooboy, that’s a good one.
There’s a few things the Japanese are really good at, and you’re looking at one when you load up that page. 
I discovered this site a couple nights ago and have wasted much time since.
A good place to go for freeware games is http://www.dosgames.com. Yep, they really are DOS games, but most will run OK under Windows XP.
Apogee put some games out as shareware in the early '90s, and the shareware versions are pretty extensive. Go to http://www.3drealms.com/downloads.html and check out Commander Keen Goodbye Galaxy, Cosmo’s Cosmic Adventure, and Duke Nukem I, II, and 3D. These are some of the best computer games ever made!
It’s not free but Call of Duty is loads of fun.
TAMARIN!!!
You’re my new hero! I found that site once and always meant to go back to it, but couldn’t find it again.
Thank you thank you thank you thank you!!!
I’ve been playing a bunch of my old favorites from that site since I found it. I need sleep.
Glad to help Dante.
I’m surprised no one here’s yet mentioned that the original DOOM was a shareware game.
I thought Wolfenstein was but Doom wasn’t.