So, searching the Unity forums I occasionally come across some good games that people post there, but don't post here or sometimes nowhere else. So I thought I'd make a list to some I've found and enjoyed. There are some on the list that have been posted already but some people still probably haven't played them so it can't hurt to be a little redundant. If anyone has any more to share, make sure the game has a web version and it's a legitimately fun and interesting game to play, and preferably game that have a beginning and an end and is free.
I Am The Knight - Very good looking and funny platformer about a superhero
Zombie Hill - very short and weird fps
Space Paranoids - FPS Tank shooter based on the Tron game
Paincube - Made by our own Nihilocrat for EGP
Sanor - by LeFishy, made for EGP, an exploration game where the world is made of numbers
Jetlane - sci-fi racing game
Arithmetism - competitive math game with lovely music (press up to play as guest)
hell is other people - interesting shooter in which you fight the ghosts of other players
Cordy - beautiful and fun little big planet clone, only 3 levels
Zombie Undertaker - survival score attack game where you try to stay alive against hordes of zombies
Hard Rock Racing - racing game with combat elements (like mario kart)
Critical Bypass - remake of the Action52 title by the same name
Tumbledrop classic - Original version of the great iphone game
Radio Silence - atmospheric fps by Terry Cavanagh made for ludum dare 17
Red Sky - polished up version of a game made by Terry for kotm
Specter Spelunker Shrinks - relatively popular platformer based on shrinking yourself
Zelda II FPS - remake of Zelda II into an fps (only 1 dungeon)
BOXGAME - unique platform puzzle game
Zagizigi - Sophie's entry for Gamma IV
Blurst- home of a few Unity web games with free versions
CosmiCube - very frustrating reflex game
Skyroad - a visually rough, but still entertaining Skyroads clone
edit: fixed zombiehill link