Swords are traditionally considered the most versatile. Though, imbuing has leveled the playing field somewhat. Still, swords has some good specials for both PvM and PvP and allows you to use both quick swords and hard-hitting axes.
Mace fighting has excellent PvM and PvP applications, not only because of the specials but also because of the damage output. However, maces are slow, so you'll need to invest some money in a good dex/stam increasing suit.
Fencing is the fastest weapon of the three weapon skills. I view it as more useful in PvP encounters: AI/infectious strike with a kryss or bleed/disarm with a war fork. That said, one of my guild mates uses fencing for PvM with great alacrity.