In addition to the above mentioned bolt guns, don't forget single shots such as the
H&R/NEF rifles. Also worth mentioning, especially if you prefer iron sights, are the ex-military bolt rifles such as the
Ishapore 2A1.
For military semi-auto .308's you're looking at the CETME or Saiga. The CETME has a reputation for being a crap-shoot.
I had a Century Arms HK-91 clone (basically a CETME with better sights) and had no issues with it. My buddy had a CETME and all it gave him issues until he broke it down and gave it a good ceaning. Others have not had so good an experience.
On the plus side, Century has a reputation for accepting returns and sending you a repaired or replacement rifle, even if you have to return it multiple times before you get one that you like. Plus, the mags are still pretty cheap.
The Saiga with a 16" barrel is developing a good reputation for accuracy, but you will likely want to convert it to a more AK style setup.
Don't forget to check your local shops for deals. You might get lucky and find something really nice. Also, there are some semi-auto .308's
Oh, and don't forget to leave some money for ammo! .308 ain't exactly the cheapest thing to shoot.