I like to use Priceline, but they screwed me on my last flight. When you bid they say it will be no more than one stop. However, if you hit the "Help" button by the one stop, it says there can be one stop AND a connection. I had to fly from San Diego to L.A., and then from L.A. to Dallas, and then on to Ft. Lauderdale. But I never knew there would be two stops until I paid for it.
I feel this is really deceiving since WHY would you click on the "HELP" if it's telling you you only have one stop?
Besides that, I've gotten some unbelievable deals bidding. I've gotten a full size car in Florida for $10 a day. I actually paid more in taxes than for a car. When I had to fly down to Florida at the last minute to attend my BF's funeral, I used their "Vacation Package", and paid almost the same thing I would have paid for round trip air, but I got a hotel room at a 3.5 * hotel, Crowne Plaza, and a full size car rental both for 6 days.
I had stayed at the Crowne Plaza on my previous trip and got tha by bidding $70 a night when they were asking $148 a night.