The best untwinked melee class is the act 2 merc. Seriously. For example, Sigon's armor+Helm and Insight or Obedience in a halfway decent weapon will be enough and that's far less out of reach for untwinked play than what might be needed for a paladin or barbarian.
Edit: A Valkyrie, a summoned bear or a horde of skeletons are also pretty useful, of course.
Frenzy barb is quite easy to play (I have one. lv 73) But he is slightly twinked. I have dual Lightsabres (I love mulling ;D) Although I did put 2 amn runes for life leech I'm not sure if that was a good move... I backed him up though. But just try to find a very strong Elite Unique and use that type of weapon.