It has the best game story I have ever seen(even the towers, called points, have quite big personalities), and it's quite a nice variant on traditional tower defence games(the arrow shoots too, and has got a special attack which draws in fire. Some of the points are quite original, also). The only con I see is that only the first 10-15 levels are free. You can get the total 100(yes, it has 100 levels), for a price of 15 dollars.
I'd have to go with Gemcraft Chapter 0 as well. I really thought Protector 3 would be up there on my list, but until a few flaws are resolved (if they ever are) then I'll have to stick with Gemcraft.
GC0 All the way man, it's got different challenges plus competing with friends for high scores if you two feel like recording scores, more customization than 1 and has plenty to do.
All TD games are almost jokes in comparison to gem craft haha. no point in putting a link cause several already have but really, both gemcraft games are the best TD games by far
Besieged http://www.towerdefence.net/games-183-Besieged.php One of my favorites, with towers learning on their own is really fun One trick for it - don't build too fast, and don't hesitate to retry the level if you fail.
GemCraft Chapter Zero http:/play/3527/gemcraft-chapter-0 'Nuff said, hands down the best TD I've been playing so far. DTD of any version isn't so much for me, but it does have some goodness.
Elite Forces: Warfare http://www.kongregate.com/games/Badim/elite-forces-warfare Not really a pure TD, but it deserves a place in the favourite list. If you don't think it should be here, then EF:C http://www.kongregate.com/games/Badim/elite-forces-conquest should be here, this one is definitely a TD.
