The best fighter class is the figther, at least to start. Pick a weapon and max out the skills for it.
Get a nice two hander, get 8 levels in fighter, 10 in frenzy berseker, and the rest in the NWN9 prestiege class. Cleave and Power Attack (and their upgrades) will do some huge DPS, and you can compensate for the lack of shield with castable buffs if you want to be able to tank decently.