Rent.com
Apartments.com

I've been using rent.com to hunt for places in Seattle. Larger, newer (more expensive) buildings have been pretty good about contacting me to answer questions and set up visit dates, so I'm pretty pleased with it. I'm quite sure that if I actually lived there I could find something cheaper than what I'll (probably) eventually end up with, but I don't live there and right now I don't care. I just want to find a place to live that's decent and that I can finalize in May for a July move-in. So yeah.