Varget is good as well. I bet a good portion of 308 shooters use either RL-15 or Varget.
Ramshot Tac is also nice. One big advantage of TAC (at least for me) is that I can't really get stick powders to throw consistantly enough from my RCBS measure to not weigh or trickle up each charge. TAC is a ball powder and meters very well for me. So if I was going to do lots of shooting I might choose TAC for just that reason.
I found 150g 30cal SSTs to be very accurate, but fairly soft bullets.
Varget sux in my 308s.
