I like Breakfree. I use it when I'm traveling, because it's a good all around product and I like the way it smells. Does a great job cleaning out powder residue/carbon. I think the only thing better than Breakfree at removing powder residue is Shooter's Choice.
It doesn't seem to do much for lead or copper fouling, but I don't get enough of that to necessitate bore solvent every time I shoot.