You don't have to actually download these games to be able to play them, but you do need a decent modem (28.8) and a Pentium (at least) if you want smooth gameplay. I will soon have some Macromedia Flash games up, but not yet. These files are links, so if they don't work for some reason, it is not my fault, and please don't email me about it (unless a link died, or quit working). Anyway, enough with the crap, here are the games:
A really good Quake/Doom-type game that you can play with your friends, without downloading! Has good graphics and gameplay, believe it or not. I was really surpised to see that it has better graphics than Doom and it is just a java applet. Better have a 56k modem and a descently fast PC for this one!
These games aren't really java, but they use ShockWave Flash by MacroMedia. So, go there, and download ShockWave to play the games. Have fun! (28.8 modem reccomended)