I just posted the Flash version of Legacy over at Kongregate.
If you've never visited its a free site that collects Flash games to play and they do a pretty good job making sure really fun games bubble up to the top.
Some of the good stuff I've come across over there:
Enough Plumbers is a crazy Mario style game except every time you grab a coin your Mario dude gets cloned! The trick is you control all of them at once and it gets so wacky, but very fun and once you get the hang of it you'll see there is a lot of subtlty, too!
Upgrade Complete is another game that takes a familiar game concept and twists it in a simple way to make something fresh. You are playing a scrolling shoot-em-up with terrible graphics and gameplay... and the objective of the game is to get upgrades that upgrade the game! So the graphics and enemies and weapons and everything gets better as you play it.
And there are a whole bunch of good puzzle games!