Troll. Regen is ALWAYS active, always working for you. Frontal stun immunity is active ONLY when you are getting hit in the face (even then you can get interrupts from push like Daldaen said)
Always > small percentage
I made a troll because I really like the regen and troll is my 3rd favorite race. My 2nd favorite race is iksar, but I already have an iksar necro.
If you really want some reading...
https://www.project1999.com/forums/s...ht=shaman+race
https://www.project1999.com/forums/s...ht=shaman+race
https://www.project1999.com/forums/s...ht=shaman+race
https://www.project1999.com/forums/s...ht=shaman+race