theengineer

I usually use Expedia - I think I heard you or your brother complaining about them a few years back, but I've always had good luck with them.

I don't think any web site offers the consistently lowest price; different web sites can get different deals sometimes. There are so many. We mostly use expedia.ca; there's also Travelocity, travel.yahoo.ca, Orbitz, and some others.

In the minimal comparison shopping I've done, Expedia has either been lowest or within a few bucks on the actual flights I've wanted. It's got a convenient interface; we've booked hotels and cars through it, and it's easy to look up what you've already booked. (I'm doing a lot of travelling this year, with four flights to the west coast and a trip to the UK for Interaction.)

I've never gotten the lowest-possible rate on Expedia myself. You have to look around for special deals, which could be found anywhere. Cheaptickets.com used to be good, but I don't think they have great deals anymore.