Shooter's Choice copper remover is pretty good stuff also. If you use any copper solvent, be sure not to let it sit in the bore too long. Follow the directions carefully, as some of this stuff will attack your barrell if you leave it in too long.

I like Birchwood Casey Bore Scrubber. It removes both nitro and copper fouling and is reasonably inexpensive. It claims to have a rust inhibitor in it also.

Regardless, I always chase the bore with Hoppe's No. 9 and then an oil soaked patch.