Airplane Tickets

[Jakey]

I'm hoping to start pricing a flight to Florida for spring break. A good friend of mine is moving just outside of Miami in December and I'm planning on visiting him over spring break. I'll probably be looking to fly out of Des Moines. Plus while I'm down there I may venture off and visit Barton and Vicious too. Any of you have good/bad experiences with the variety of online ticket agents?

Orbitz?
Priceline?
Expedia?

Thanks