Towers in Space is an excellent TD with great voice acting and very challenging. Knight Defense is very good as well, unique to your standard TD affair. I like Vector TD as well but that game is simply unplayable on the Ipod Touch, wish they would fix it.
GD and one more... My favs are geoDefense and geoDefense Swarm, but I that's probably cuz I made them. But of the ones I didn't have anything to do with, and I don't think mentioned already... I liked Warp Defense. Give it a try, it's fun. David
My favorite Tower Defense games include: 1. Gemcraft 2. Gemcraft Chapter Zero 3. Desktop Tower Defense 4. Desktop Tower Defense Pro.
Gemcraft is comming to iPhone so you will get your favorite soon. Also nobody mentioned protector the planes! Thats also on iPhone thought I don't think anyone knows it. If you dont mind old school graphics, some of the best TD gameplay on the iPhone.
Pixeljunk Monsters Deluxe on PSP is the best Tower Defence I've came across as well but I do have a few good ones on Ipod like the sentinel series and defender chronicles in fact their all pretty good really. Here is my Tower defence folder
On iOS: #1 Dungeon Defenders #2 The Creeps/HD/HE #3 Plants Vs. Zombies iPad #4 iBomber Defense #5 Starfall Have not started Sentinel 3 or 3 Kingdoms yet. Other OSes: #1 Defense Grid (oh yes) #2 Toy Soldiers (Xbox) #3 Pixel Junk Monsters (PSP edition) #4 Savage Moon (also forgot to mention Battle for Hoth from these guys) Have not started Monday Night Combat.
It can be if thats how you want to play Note: Your character is blacked out because we don't want to unveil all of the new ones yet, coming up in the next update.
One that has gotten zero attention but is in fact pretty impressive is Two Worlds 2 Castle Defense -- basically an iOS promo of the recently released PC/Mac/Console open world RPG. It's similar to that Lord of the Rings TD game that came out in December, but with much better graphics and animation, as well as much faster and varied gameplay. Only a lite version is available so far; the full should be coming out soon.
Are there any good TDs coming out that we should be watching out for? I think I already have most of the available titles that I'm interested in.