Actually, I think that you can have fun with each army, in the right situation. For instance, you may struggle a bit with Army of the Dead when fighting against wood elves, while it may be sooooo enjoyable against trolls, orcs and others
I like the fact that you can shoot in combat with evil. It has brought some laugh around the battlefield each time an arrow miss its initial target
I've never played competitively but I've played :
- Dwarves : quite fun, I really like their "tank" attitude. I've always loved dwarves in Fantasy, the background and the rough behaviour :p
Plus, in game, having a shieldwall advancing on the battlefield, and having the enemy asking the score to wound them with regular bows, then you're saying "heee, 6/4" and watching his face is soooo hilarous :p Then he shoots at your bowmen, and you say "you need a 6 to kill"
- Isengard : crossbows are enjoyable, but I find the army a bit boring and repetitive (when playing uruks) :s
- Mordor : so many possibilities. I always try new builds. You really can field what you want, and what you need ==> lot of fun with Necromancer (played once), Morannons, Wraith and blackguards, Kardush killing his own models...
- Harad : I've not played them a lot but I quite liked the style. Some unique abilities too (golden king for instance. I haven't played it yet but I've planned to do so quickly!!!)
- Minas Tirith : versatile. I like the fact that the opponent thinks "they're just men, they will lose" and then you prove he's wrong :p some good units (Denethor in game is a lot of fun with his special rule :p)
- High elves : same as uruks, strong but I think they're a bit repetitive
- Rohan : I've never played them well, so I don't like them for the moment
I'd like to play hobbits, good monsters such as Treebeard (I've only played with Gwaihir once) and evil biiiiig monsters (dragon, gulhavar,...), or Moria with beasts (I think it can be quite enjoyable and a bit disturbing)