We rent through Florida Sun Vacation Homes. They've been recommended by others on this board. They offer 15% off on stays of 7 nights or more, and we usually stay 8-10 days. When pricing our trip for next year, I sent inquiries to 6 properties on vrbo and only one came below the price quoted by Florida Sun Vacations. Their properties look exactly as pictured, and the homes are spotless (very important to me!). They also don't make you strip the beds, start a load of towels, etc. upon departure which is required by some other management companies.
We stay in Windsor Hills but they also have homes in Emerald Island, Sunset Lakes, and Windsor Palms which are less expensive than Windsor Hills.
Another company that has been recommended a lot is All Star Vacation Homes.
Good luck with your search.