If you want to go with a very large company known for having a reticle designed specifically for the .308WIN, it's hard to argue with the Nikon M308. It's around $360 right now on the web.
If you don't mind going with a smaller company, I've had excellent success with Athlon scopes. You could use the Athlon Argos BTR 6-24x50, which is around $315 on the web.