For a while I was using the crappy little cage that Winnie was in when I got her (barely suitable for a budgie) but after doing some research and considering a bunch of different choices I ended up picking the Avian Adventures Poquito Hotel (http://www.amazon.com/Midwest-Avian-Adventures-Poquito-Platinum/dp/B0018CDYVG) , which I've been very pleased with.
To me, the major advantages are that it is "open" so the bird can see out of it, unlike some pet carriers, and that it's large enough that I don't feel bad keeping my Quaker in it for a couple days when I have her at my parents' or at the beach for the weekend. It also has built-in food dishes, a slide-out cleaning tray, and a perch built into the handle. Disadvantages are weight (it's like 25 pounds, so it's not really practical to carry around for long periods) and the door latches are kind of weird and get stuck sometimes. Other than that I'm very impressed with the quality.









- Sheldon