There are two questions:
1. The best company
2. The best company to use for a particular domain w/re to revenue
You'll get alot of opinions re: 1, although there are a few non-contenders like DomainHop. 2, is up to you to find out .. if you have traffic .. you'll want to circulate your domains through different parking companies. Or get some tips here on this forum, depending on your domain(s).
For sales, try Sedo.
VRC