There is one good td... Kingdom rush. The rest are just dull.
First, KR is not even a tower game. You can move your troops and do some strategy this way instead of being stuck with having a tower and simply upgrading it.
Second, KR really suck. I've never been able to try more than two or three levels before throwing the towel. It's graphics are bad, there is no balance, the first few levels are way too hard and there is no obvious or less obvious chokepoints to start a level. It's like you really need to build different kind of troops in a line and hope that the next wave will be stopped before you run out of troops. Real TD games are like that, troop defense games like KR should not!
There is a game which is similar to KR which got out recently which is 10 times better. It is called Incursion. Better check it out. ;)
