Unfortunatly, you're more likely to get a response if you ask who people WOULDN'T recommend. If you currently have an agent on board that you're not happy with, is it worth going through the old threads here and pulling out some of the advice given? Failing that, approach some agents and set up meetings. Time consuming but neccessary, even with recommendations.
What sort of management agent? One contracted by a management company to take care of the day to day management issues associated with a private apartment or housing development? Or one to manage a specific privately held rental property?