Sorry for bumping an old thread.
BTW, since I've never played multiplayer, a lot of my rankings would go towards how well they can clear maps as well as the first few weeks.
My favourite town? Rampart. They can clear even level 6 stacks in week one. One of the best rushers as well. And you can't go wrong with a level 5 horde building. Most cost effective unit in the game, and it's only a lvl 3 unit. Rampart does have its weaknesses though. If you get careless and the enemy wipes out or even blocks your elf stacks, what else can you use as an offensive force? Lvl 6 and 7 units are only mediocre, level 2 and 5 units are only there to protect your elves, silver pegasus are fast, but very fragile, and master centaurs are good, but they're only a lvl 1 unit. So as long as you keep your elves alive, you're golden.
Castle - great units, but really slow buildup. You can either get cavaliers OR angels OR 24 griffins on week 2. Cavaliers require too much wood, angels require too much gold, and if you want to go for griffins, well, you might not be able to clear high level stacks. Extremely powerful once you have all the units though. However, aside from archangels, your second highest unit speed is 9.
Tower - best shooters in the game, but heroes aren't that good, and requires a lot of resources before you can get a decent fighting force. If resources are rare you'll be relying on master gremlins for quite a while. However, the only level 7 shooter, and high HP on a shooter is very important.
Inferno - 6 efreet sultans in week 2 means that you can clear the majority of the map. Other than that, their non-upgraded units are probably the best in the game. Regular gogs, efreets, and devils can make a decent army. Once upgraded though, they fall behind, with the exception of cerebri. In long games, pit lords and demons make inferno like a mini-Necropolis.
Necropolis - Vampire lords PWN. That is all. Probably one of the most invincible non-lvl 7 units in the game. Opponent needs to bring elemental or non-living units in order to deal with VL's. However, the highest speed beside ghost dragons is only 9, and if you don't upgrade your bone dragons, any army with a unit with a speed higher than 9 and mass slow can make you a sitting duck. Worse yet, you're basically upgrading the worst level 7 unit in the game.
Stronghold - Probably my second favourite due to strong units that are available right off the bat, but I'm turned off by the ridiculous resource costs. In a map with only ONE sawmill and ore pit on my side I can only make 2-3 dwellings on first week then I'll have to build a resource silo. Lack of lvl 4 and 5 mage guilds kind of hurt, but it won't really be a problem if I capture another town. Excellent heroes as well. Somewhat too dependent on thunderbirds though.
Dungeon - In a way this is like a mini-Rampart. No uber-strong units like grand elves, but also no uber-weak units like dendroid soldiers (at least, in a battle). Scorpicores IMO are actually quite decent; speed 11 allows them to take care of shooters well. The main problem is what to do before they get red dragons - they have to spend a significant amount of gold in order to afford a decent fighting force to clear the stacks, which is bad because they're also resource dependent. However, best heroes in the game, hands down.
Fortress - Probably my least favourite. Like Stronghold, they are too resource dependent and lack lvl 4 and 5 guilds, but unlike Stronghold they don't really have a decent force to clear stacks and to rush the opponent. Mighty gorgons are only good with killing level 6-7 creatures so I guess fortress would rule on maps with a lot of dragon utopias or frozen cliffs. But on maps without those buildings fortress would fall behind. Great might heroes though, but I would still prefer offense over defense. Dragonflies may be fast and all, but they crumble very quickly, especially when facing strong stacks.
Last but not least Conflux. Yes I know it's horribly broken, but that's why I'm playing UndeadHalfOrc's patch. I have to say though, with phoenixes being nerfed to 2 per week I find myself relying on magic elementals most of the time. They are amazing, yes even better than naga queens. Great might heroes with unique specialities, and magic heroes starting with magic schools. The problem is that most of the units are quite useless without the upgrade.