Troll is the best stats wise. Higher starting dex+str than the other and will be the most effective combined with yellow celerity.

Kobold is my favourite though because i like small chars. It makes it easier to target lurikeens that are immediately in front of you and slightly harder for opponents to target you etc, being small is nice in my opinion.

If you decide to make a zerker instead then Troll is the only option if you dont want to be sub-optimal.

its funny to see the other opinions here...

but it is how it is

be sup-optimal or be optimal and for all melee classes...troll is still the best!!