If I were to rate best times of year to sell, this would be my order:
1. Spring to early summer
3. Late Summer
There are, of course, pros and cons to every season. In the winter there are not as many buyers (they are still out there), but there is also not a lot of inventory. Late summer tends to have a lot of buyers or their agents out of town, so the tension of the market isn't as intense. In the Fall, buyers tend to get serious again after summer vacations. That's my two sense from what I've observed!