Tower defence flash games!

I love ALL defense games, and not just tower defense.

Here are a few good defense games I like:
Crimson Warfare - This one uses base building as well as being a defense game. It's moderately challenging, which I like.
Defend Your Castle - This is a classic.
Mastermind : World Conqueror - This one is also base-building and it's a very involved game where you play the role of a mastermind that sends out his minions to corrupt politicians.
Cursed Treasure - This is an extremely balanced game, but suffers due to lack of levels. Also, the higher levels get a bit monotonous but it's worth the struggle. I fully beat this game and it's worth my time.
Onslaught - This is the perfect tower defense game and has a hardcore community to go along with it to adjust for balance.

I'm sure there are others that I forgot...

I've only played Onslaught and Cursed treasure out of those ( I think ) I'll try them out later when I have time :B