I'm not about to play favorites, but in terms of race/class combo effectiveness:
Gigz > Miji > Krom
Shadowmeld is an absurdly useful racial for non-stealth classes. Preists (particularly Shadow Priests) greatly benefit from it. They won't see your ranged attack until it's too late.
Escape Artist is good for Warriors, because it gives them even more anti-CC. Berserker stance, Charge, Hamstring, Intercept / Escape Artist if necessary... was meant to be, y'know?
Krom, well... he's just kinda Krom-y.