There have been some pretty amazing flash games. Some have amazing graphics, some are unique, and some are just fun altogether. I figured we should make a list of some of the best

I'm a Kongregate guy, just to say. Here's a few of my favorites:
Upgrade Complete!
Warlords: Call to Arms
Age of War
Learn to Fly
Epic War*
Shift*
Bloons Tower Defense*
* indicates there are 4 total int he series. No mark indicates it is a stand-alone game

PS i finally decided to google how to title links like this. This will come in handy Hope some people enjoy these!

No particular order:

Gemcraft
http://amanita-design.net/ everything from these guys
kohctpyktop my absolute favorite (not for the simple minded...)
http://www.bankrungame.com/ Not really a game, but it's much fun and a great concept
everydaythesamedream Can't think of a proper description

Have fun playing!