I've ordered from both Ribble and Wiggle with no complaints about either. I actually prefer Ribble's untracked shipping (as long as there are no problems!), since Wiggle packages require a signature and there's not usually anyone at home during delivery times.

Very good service also from Nashbar, JensonUSA, and Merlin.

Very poor service and practically non-existent communication from Race View.

While on the topic of online buying, I am wary of buying bike parts on Amazon. Always look at who the seller is. I've ended up with sub-standard counterfeit parts from no-name sellers on Amazon.