my pals MF using sorcs or pallys but i stick to my ik/mf barb for various reasons:
lvl 30 BO rocks.
IK set socketed with Ptopaz grants a base mf of around 120%
Dual alibabas + 200% (if ur lvl 80 and if u socket it with mf jewels abit more)
Gheeds
about 50% from mfsc
Sub total: about 400%
I use a lvl 85 barb merc with the following eq:
Upped P-topaz skullders: 125%
P-topaz Arreats: 24%
Shael-ed 247ed GF
Total: about 550%
I do meph runs with him exclusively and it's great fun because i have to run there, jump over the blood moat, cast TP, go back, Battle Cry, Concentrate with the Stone Crusher, beat him 2 a sliver, switch and watch my merc kill him.
I know my mf style is abit outdated...but it works and furthermore, given the massive defence and hp the barb has, it's almost impossible 2 die. I just Howl away the dolls to clear a path for the merc.
Sorry if i'm ranting about my Ik/MF barb....it's simply because his so damn effective!
But if you wanna have a all around good MF-er, a hammerdin will be a wise choice, they are abit hard 2 play (alot of players play them wrong) but with enuff practice, hammerdins can sweep all before them.
My hammerdin is at lvl 42....i'm training him to clear certain areas that my IK barb doesn't like ;-P