Crete

One always gets better answers when sharing more information. Your posting history shows that you have done R Steves tours to about 5 places, and also previously spent a month in Greece, mostly on mainland & several islands. From your terse entry, many may think you are a newcomer to Greece who may want a complete package.

I have been to Crete 5 times, do not see much on forums about Crete travel agents -- rather agencies that do day tours. There is splendid new one in Chania, small-bus tours (12 people) with interesting itineraries (down Imbros Gorge, ferry to Loutro & back, and also half day outings to vineyards, olive-oil farms, etc. It would help if you shared more about your interests ... ancient history? medieval? hikes? nature? food? Also, do you have preferences, West Crete vs East? Will you rent a car? Are you solo?

Have a look at putting an itinerary together without a travel agent. What are your interests? Are you looking at more than one base and will you be renting a car, using public transport or booking organised trips?