Pretty much just the Krausers and it's variants (Star - smaller), or the BMW touring bags.
The touring bags don't come up for sale real often, and they don't last long when they do. But of the two, they are the ones I would recommend. I just bought a new set to replace ones destroyed in a crash, and the final bill is not for the faint of heart. You have to buy the locks and reflectors and badges all separately! But boy, are they nice! And I just had the six locks keyed the same as my ignition key!
But those are the only two common options I know of for your standard loops.
A lot of people have made their own bags that attach to the loops. Someone, and I think it was on here, a fellow in Alaska for sure, made some really nice bags. I don't remember if they mounted to loops, but I'll try and track down the thread.