I agree. For the most part they all use the Sabre system and get the same prices. You can sometimes get a better price from a consolidator or "last minute" place. But between the major guys, Expedia, Travelocity, and the like are all about the same.

You may also check the travel section of the Sunday papers. At least here on the east coast, they have a lot of package deals that include the air/hotel/some food/and transport. Usually a decent (not great) deal. Or you can check to see if National flies into your home airport. They are HQ'd in LV and have some terrific prices. And a strategic partnership with Harrah's/Rio (if you stay there).

For work, I have been using BizTravel. They are the online part of Rosenbluth (big here in the Philadelphia area). They have a unique differentiator. If you buy a ticket through them and are using one of the "preferred airlines" (USAir, American, British Air, a few others) AND the plane is late, you get a check in the mail. I have a stereo system I bought from a cancelled flight.