If you don't have a semi-auto military-style rifle (as others pointed out, not all you listed are "battle rifles"), I'd suggest an AR-15.
Don't let the direct gas operating system ("craps where it eats") criticism get you. For a civilian shooter who is going to keep his gun fairly clean you'll be fine. Don't let the 5.56 sucks criticism get you. You don't have to shoot FMJ. Load yours up with Hornady TAP ammo and you got a stopper on you hands.
For an essay of the positives of the AR15, surf this link:
http://ar15.com/content/articles/idealRifle/
Also 223 ammo can be had cheap and shoots flat. Go ahead and buy a post ban in advance of the AWB sunset and add that flash suppressor later. USGI mags are also falling in price.
Other rifles mentioned - like a FAL or M1A carbine 308 - are good rifles to round out the battery. But if you only had one and wanted a general purpose rifle the AR15 is my suggestion. Besides, there is a plethora of goodies you can buy for it!
If you decide on the AR15, the next thread would be "which AR15?" which is almost as controversial as "AR vs. AK?"
By the way, my recommendation would be a Rock River Arms "R4" flattop carbine, A2 stock, chrome-lined barrel, EOtech rev F sight, Wilderness tac sling, battlegrip. I'm not into the forend rails as they are heavy and I don't have a lot of stuff to tack on the front end of the rifle anyways. Carbine=light & handy. If I wanted a gun to weigh as much as an M1A or FAL, that's what I'd use.