I predominately order from saltwaterfish - I like their free shipping promos, and fedex service. I've got no complaints - I had one shrimp arrive DOA like 7 years ago - just follow the policy (snap time stamped photo upon arrival and raise claim immediately), and they made me right on the next order. No one is perfect, and no order is the exact same so I'm sure others have opinions about them.
I will occasionally buy from LFSs after I eyeball a critter for some time - if its my first shopping experience in a LFS I'll ask if they'll except a deposit on a newly arrived critter as a litmus test on whether or not they're confident in the quality of their livestock. Being new here, I can't wait to test out some sponsers, and soforth - when it is time! Things are startin' to groove right after a move, transfer, and upgrade. Gotta get my stability jivin' just right.
Anyway, I'm ramblin - Every vendor is sure to offer some good and unsavory service at times. Sometimes it's the issue resolution that sets some vendors apart from others.