Since this is my first play through of it I went with:
Can't wait to finish this up and go back to try some more combinations!
That's the same combination I went with on my first play through.
Soldier is the best rounded for combat I think since you get all the weapons except SMG and you have high hit points.
I played as a female renegade vanguard on my second play through and it was like playing a different game. Renegade Shepard is a thug and a complete asshole/bitch. Plus the vanguard charge ability really changes combat from cover shooting to up close and blasting everyone away with your shotgun.