I wouldn't use any travel agent other than Travel Authority, located in Pennsylvania, but they have clients world wide. They ALWAYS give me better deals then any internet agency quotes or any other local agency quotes.
I have had several family/friend group cruises and have more then happy with the service they provide. They not only provide good service they also include free "extras", like personalized destination guides, photo albums with my groups name on them just to name a few.
I usually deal with Linda but anyone there is more than competant. Their email is email@example.com