Warlock, in my opinion. Other people will say Alchemist or Headhunter based on personal preferences but honestly I'd be happy with a Warlock
But the best starter character is probably a fighter. They have nicely balanced stat points and melee is easier than caster, for a new player at least
The best route would be to make a fighter and dump every stat point into strength. Then try to get weapons and armour with enhanced effect and charms with dex. At level 0 (tier III) aim for 30ee and 10 dex or more and then just buy higher level slightly better gear when you need to upgrade with the same or higher stats and you should be golden.
There are some guides stickied around somewhere but it's pretty straightforward for the most part (except not at the same time
)