I agree cruisecompete.com is a good place to start looking at prices. However, I have never actually booked via cruisecompete. I have always been able to find even better fares by doing just a little more research. The trick is to know exactly what you are looking for, be flexible on the dates, and be ready to put a deposit down immediately.

I recently used vacationstogo to book a cruise to Patagonia. I worked with an excellent agent who was able to get me the last mini-suite at a very good rate. Prior to calling vacationstogo, I had called NCL directly and was told the category was sold out, but vacationstogo was able to prevail and get me the cabin I wanted for the advertised price. Bookings/cancellations can happen very quickly when inventory is tight.

I have also found that booking direct provides no benefit. In fact, sometimes the result is counter-intuitive. On a cruise I was booking this summer, my direct call to MSC resulted in a quote $500 higher than an agent was able to obtain. The only explanation for that is that cruise lines may prefer you use a travel agent so they can reduce costly staffing and administrative expenses.

Your best success lies with the combination of the person you work with and the allowances available within their organizations contracts with the cruise lines.