I ordered a set of DR Sunbeams from JustStrings.com for my fretless six and they accidentally sent me a set of Nickel Lo-Riders instead. Since I'm new to DR and both sets are similar nickel strings, save that Lo-Riders are hex-core and Sunbeams are round-core, I decided to give em a try.
For the heck of it, I emailed JustStrings to let them know about the error; they apologized for the mistake and sent me a set of Sunbeams free of charge and no questions asked! That's what I call great customer service. As I'm sure many of you already know, they have a huge selection of strings, competitive pricing, and super quick delivery, but this exceeded my expectations.
http://www.juststrings.com/