Troll- Regen, good str/stam starting stats, JBB, 36s clickie snare(innoruuk), bash
Iksar if you plan on poop socking end game velious. (regen + higher AC) (no bash)
http://wiki.project1999.com/Robe_of_the_Azure_Sky
Ogre if you want to look like a wall of ugly that can get hit in the face with Frontal Stun immunity, bash.
Barb if you want to win fashion quest (Barbarian Spiritist`s Hammer), JBB and can enter all the good / neutral cities, bash.
Regen is life+mana for a shaman. Don't let people make you think that regen isn't an big advantage in the long run. You can canni+torpor but regen is always on, even when torpor ticks end.
Level 55 Form of the Great Bear:
Ogres into a Grizzly bear
Troll/Iksar into a Kodiak
Barbarians into a Polar Bear
Shaman is a very Skill > Race class.
Pick what you want! Stop listening to what other people tell you is best. Best is very opinion based usually.
Just don't go ogre. They're fat, dumb, stinky & ugly. Listen to my opinion!