Well, it depends on what you wanna do. One-handed, axes are much better, since they can get 6 sockets on the berserker, which is the best one-hander in the game, meaning you can put just about anything you want in one (even if it's just pgems or small runes). They're also great since you can use them in the blood recipe, and because they generally have good damage and base speeds, meaning they hit breakpoints a lot easier.
Two-handed, on the other hand, maces are a lot better. The thundermaul is the most damaging 2-hander in the game on a swing-to-swing ratio, since it has the highest damage and gets 1.1% damage per point of str instead of 1%. Maces also have some nice unique one-handers like Nord's, but they're typically very slow and difficult to hit break-points with, and none of the one-handers can get 6 sockets; they also can't be used in several of the runeword formulas to begin with.
For my 2-handed Zerker I went axe. It helped that I found a rare feral axe that was 293% enhanced damage with +16 ar/lvl and +.5 to max dmg /lvl. I think one of the factors that is most important to consider for pvm is what kind of monsters are you going after? Most of the act bosses and Baal's minions are demons - axes get a 150% enhanced damage boost against demons so the stated damage of a particular axe is not correct when you calculate what the damage is against Baal or Uber Diablo.
Go Axes! I was converted to axes after reading Hal's guide, and finding that my CB was far inferior to my Berserker Axe as far as Weapon/Shield was concerned. Plus i get to play with Doom, Beast, AND Botd. Fun Factor 10. haha alright thx for listening.