Gonna have to go with Soldier. As annoying as it is getting hurled down to the ground multiple times, I still find bullet-hosing my way through enemies is the best (and the most fun) way to go. This may be due to my dislike of fiddling around with stuff, I like my combat as simple as possible. Its not that I can't see the value of biotic powers, I just have more fun in a plain old shoot-out. I do tend to bring one of the biotics as back-up however. It's a pain how they don't heal themselves... another reason why I like the soldier class. Free healing!
My typical team? Kaiden or Tali for hacking, with Kaiden acting as my biotic, and Ashley/Wrex for muscle, with Wrex again acting as the biotic. So if Tali's coming, I pick Wrex. If Kaiden's coming along, I take Ashley. Either way, I have muscle, biotics and hacking available. I'll occasionally take Varrus instead of Kaiden. In this case, I'll take Wrex.
One of the reasons for my pick of the soldier class is that I don't trust my team to keep themselves alive. I may need to put myself in the firing line to stop a wayward team member getting shot to pieces. So a meat-shield soldier is in order.