I'd suggest the Bushmaster ACR. Price is supposed to be $1500-$1600, modular design and construction (3 stocks, 3 forearms and a number of barrel lengths to choose from) so you can configure it as a SBR entry carbine (If you're willing to do the paperwork and pay the $200 NFA transfer tax.) on up to a precision/marksman's rifle and anything in between. It has ambidextrous controls, is 1/2 lb. lighter than a comparable AR, uses AR/M16 magazines, has gas piston operation and a quick change barrel system.

Another advantage with the modular design is they have plans to release conversions in various calibers including 6.8 SPC and 7.62x39 so you'd have even more versatility without having to buy or carry extra complete rifles. Myself, I'm planning on having an extra 18" barrel made in 6.5 MPC which is more appropriate for deer, feral pigs and black bear, (.223 not being legal for deer hunting here.) and only requires changing out the barrel as you'll see from the videos.

AR15 Shot Show 2008 video

YouTube-Future Weapons:Magpul Masada (Bushmaster ACR) video

Only drawback is that it hasn't been released for sale yet but it's due out sometime this summer.