Iksar are terrible, ignore them.
Troll regen is great for the early game, but eventually becomes somewhat pointless, especially in Kunark. It's never completely useless but I wouldn't roll a troll with their 20% exp penalty and lousy stats.
Ogre would clearly be the winner for best stats and frontal stun immunity.
If you think you'll in whatever guild that will be getting first CT kills, you may want to go Barbarian solely for this:
http://lucy.allakhazam.com/item.html?id=11647
If you go Ogre you can get one of these mid-game:
http://lucy.allakhazam.com/item.html?id=13359
Ogre is the sure bet with better stats, but barbarians are still decentish. If you can get your hands on a Barbarian Spiritist's Hammer then it somewhat makes up for the stat / frontal stun immunity disparity. But in conclusion with all that considered, I'd still roll an Ogre if I wanted to choose the best race.