If you are in their prime coverage area, Clearwire rules from what I understand. A close friend of mine has it and is very happy with it. He's not an online gamer, so latency isn't terribly important to him. He downloads and uploads massive graphics files for a living and his download speed is 500 kb/sec +. His upload is only about 100 kb/sec which is still pretty fucking respectable.
I had the Sprint PCS card and was relativley happy with it until I moved. In my old residence, it worked quite well in terms of download speeds (was up to 150 kb/sec at times - usually around 120) and decent upload speeds (about 40kb/sec). In terms of online game play - it was about the same as a modem in terms of latency (average ping to a WoW server ballpark 400ms) but much better in terms of bandwidth (patching, zone changes). At that time, I would have recommended it to anybody.
Then I moved. At my current residence, the Sprint card sucks ass. It's basically about the same as a bad analog modem connection now. Good thing that high-speed is available at my new house (was installed on day 2 of residency).
Moose