Dragonforce around 7 or 8 times
Turisas...over 24. I stopped counting
There are more, I just need to sort my brains out

Oh yeah, this thread.
Adding:
Macabre x 2
Forbidden x 2
Devin x 2

I need to update my list again :p

Devin Townsend (alone or with the band) (11)
Dave McPherson (5)
Lumsk (4)
Nightwish (4)
Pain of Salvation (2)
Kamelot (2)
Danny Cavanagh (2)
Triosphere (2)
Sylsosis (2)
Cryptex (2)

In no particular order:
-Kamelot
-Rammstein
-In Flames
-Megadeth
-Slayer
-Iron Maiden
-Amorphis, Turisas and bunch of other Finnish bands...