From the way you describe them, HalfAxe, with words like "big" and "fat" and "oaf", it sounds like you consider them slow. But Jotun are actually very fast for infantry units. Long legs means long strides.
I think their main weakness lies in attack Ratings, which, even for the elite Jotun Hirdmen, are only 10-12. Cavalry, which tend to have really good Def skills, like Royal Guard, Centaur Warriors, Knights, Black Knights (I have doubts about Knights of Ulm, whatever you call 'em. Don't play Ulm much), Knights of Avalon and Van often pose a problem for my ice giants.
Another very good way of combatting giants, as long as they're not using a Woodsman or Huskarl dependant army, is to bring out the heaviest weapons available and the burliest men. I'm not a big fan of ranged combat, but if you absolutely want it, Crossbows and Arbalests can punch through the giants' Chain Mail Hauberks like pudding if they manage to hit in the first place. I think good anti-giant infantry are
Imperial Footmen with glaives, the infantry of the people! Celestial Soldiers and Demons of Heavenly Rivers work well too, I mean, what CAN'T they do?
Machaka Hoplites, but that's kind of a stretch
Elemental demons, all nice and strong if I remember right. The Devil gets the added bonus of having a fork. They'll provide all the punch you need for Abysia and Mictlan.
Slave/Elite Warriors, once again, forks
R'lyeh slave... I dunno, were they Guardians? Forks, but consider Lobo with Illithids. The Lobo policy of quantity vs. quality does well against Jotunheim as tanks while Illithids can bLast away
I've never actually used Barbarians or Lizard Warriors, but I guess they'll do in a pinch.
Marignon Halberdiers and Swordsmen, (see Celestial Soldiers and Demon of Heavenly Rivers)
Maybe Skinshifters, I've never been in a Van vs Jotun situation. I'm sure Einheres would get a strength bonus once they berserk, but they probably won't survive the first hit by a giant.
I don't think Pythium has any reliable response to Jotunheim. Their best bet would probably be the Hydra.
Atlantian War Shamblers are good, theoretically, but I haven't used them much.
Ulm has infantry with two handed weapons, which generally pack a very satisfying punch. Black Woods Rangers would probably work well too, their high prec is good news, as are their axes instead of short swords in close combat.
I don't play Caelum much, but with them, I would probably depend on the Mammoth, same with Arcosephalean elephants.
With Man, I would place my bet on Wardens, but you're probably better off taking advantage of the giants' poor attack skill and use Knights/Knights of Avalon.
Ermor... relax, the giants'll have a hard time getting anywhere near you with your death domain. Now go grab some ice cream or some undead wenches.
With Pangaea, even though minotaurs carry a big axe, you don't want them anywhere near giants. Better to take advantage of the giants' poor attack skill (deja vu) and use Centaur Warriors.
Am I forgetting any nation?
Edit: For the SC question, that's the current imbalance, or shall I say "cheese" in this game. Someone's already said fliers, and I find that they work the best. Even fielding your own SC is risky, at best.
Edit2: In response to the first post. Dwarves use guerilla tactics? Maybe I'm thinking of different dwarves, or you're thinking of the normal fantasy elf. But aside from that, guerilla tactics are horrible. Whenever you retreat, even on purpose, your units end up scattered in all the neighboring provinces, or die when they retreat into an enemy one.
Edit3: God bless Norfleet... he'll need it.
[ June 23, 2004, 06:24: Message edited by: HotNifeThruButr ]