In the internet age, we know this is a common question that deserves an honest answer. 

1)  Travel agents have access to many deals and specials that are not available to the general public.

2) Travel agents also have specific destination knowledge that can be very helpful in planning a vacation.

3) A travel agent can take the work and stress out of the planning, scheduling and booking. A travel agent is there to do this work for you and find you the best deal. This means that you could call up your travel agent and say, "We are thinking about taking a cruise for our 30th anniversary. We would like something in a warm climate and our budget is around $xxxx dollars.  Can you make some recommendations?"  Or, "Hey, my family is in New York for the week and I am thinking about flying out to stay with them for the weekend.  Can you let me know the best deal on a package that will include air and a hotel?"