Couldn't put it better. I have The Creeps (what's better is they have different critters for each level), GeoDefense, Defender Chronicles, and something else. I'd recommend Defender Chronicles if you're really only prepared to get one, and be prepared to be challenge because it's really hard (but worth it).
For me, the highest replay value is in GeoDefence and Creeps. Here's why: GeoDefence has more than 30 unique maps. 30! So it's not so much replay as it is "play" in the first place...and many of the maps take me a long time to beat. (I *still* can't beat that darn "x-factor" map on hard!) Creeps also has a ton of maps (although they are variations on three main themes, each map is different) and with the badges (kill all creeps, don't sell a tower, beat it on hard, etc.), I find myself replaying different maps and different playmodes constantly. I can't resist hearing those vampires say, "It buuuuurns!" Thanks for the tip on Besiegement, whoever said that. I picked it up yesterday, and it's great!
You know, I wasn't actually as keen on Besiegement as I have been of other TDs. I don't know why. I mean, it was definitely worth $1 (actually, I think I paid more for it) but once I finished all the levels, I didn't go back to it. I think Elemental Monster TD may be another TD that doesn't do well replay-wise. I mean, I loved the game and it's very worth having, and it's great while you're playing it, but once you've unlocked all the cards I think it suffers from a replay standpoint. Frankly, the TD I replay most often is The Creeps. Not because it's the deepest -- it's not -- but because if I just feel like a quick, casual, fun TD game, I can jump in and blow up the cute monsters that make funny sounds when I kill them. (The zombies are my favorite. "BRAINS!") It's fast and fun without (usually) making me beat my head against the wall.
I want to love the Creeps, and I did at first. Its just not hard enough. When the new version came out, I tried it again on hard mode. On each map, the only question was would I get all the badges on the first try, or would I let a single boss get by. Great production values, great sound, graphics, etc. Just to darn easy.
Another for Geo Defense. If I could only have one that would be it no question hands down. If you let me have another I would get fieldrunners. It's a little different as you actually have to make the path that the enemies will take.
I really like the Creeps, maybe the only TD I like on iPhone. The art style is great and I love the special weapons
ugh, so many choices...i think its hard to really recommend a good td because they are all so different...to me it seems like not recommending one would be a more telling sign as to whether its worth your time and money or not... ive always fieldrunners and 7 cities myself i did not like creeps but it may have been because i didnt put the time into it. i was just turned off initially for some reason and never came back...
For me, the ones that are high on MY list are: Star Defense - Nearly got caught up in all the negative critisism, but in truth I'm so impressed with this beast. It's so polished, and with a fast forward button it would be perfect. I'm playing on normal mode, and am on planet 3. It's already quite challenging. Geo Defense - Again, beautiful presentation, and really unforgiving difficulty make this a game to tackle in those moments when I feel like a real challenge. Can't fault it really. The Creeps - Guess what.....beautiful presentation, and who doesn't like to hear Dracula's laugh out loud 'It buuurns'. Never gets old. Dungeon Defense - Looks and sounds really great. Lacking in units making it a bit on the dull side sometimes, but I keep coming back to it. Zombie Attack - When I feel like something a little bit off the beaten track.
I don't see anyone overrating it In fact all I see is people having a good old anti ngmoco/Star Defense bickering session. I'm not joining in. Why? Because I think this game is good. Although not the most challenging TD of them all, it's not a walk in the park either. Also, I honestly don't want to burst a synapse every time I play a TD, sometimes yes (in which case I get out Geo Defense), but other times I just want to bask in the atmos which SD does really well. I love spinning that globe around. It does feel like an epic battle is going on when you play with earphones or hook up to speakers (Bose in my case), and hear the rumblings of war going on on the other side of the planet, only to spin around and be in the thick of it again. So in short I play SD for the escapist in me.
The best is ElementalMonster TD. It's polished, lots of fun, and contains SOOOO many hours of gameplay. I was playing this game so much I got a fever from my body overheating.