Biztravel.com

I don't understand why biztravel.com is getting such poor ratings. I have used this site to purchase airline tickets 3 times, and have always gotten a great deal. They even have a guarantee on some airlines so that if your flight is late, you get reimbursed for your trouble. On one of my flights, I arrived an hour and a half late, and got a $200 rebate! My ticket only cost $220, so I got almost all of it back. They have since changed their rebate policy since it was getting to expensive, but you can still get up to $100 back. The customer service line is friendly and helpful, and the website is easy to use. I definitely like it.

Always has the cheapest airfare. Has technical difficulties often, though.