I've tried several methods so I can understand your dilemma. I am currently using the Leapfrog LF-20 (I think). It runs at 2.5 GHz and it's "OK". For video, it's only composite so the pic is decent but not great. For me it's fine, since I only use it to transmit my DirecTivo from the bedroom to my cheapo kitchen LCD.
However, there are some problems. It runs at 2.5 GHz, which is a crowded band. You'll have noise from a microwave, REALLY bad noise from wireless 2.5 GHz phones like V Tech, and possible video/audio noise from an 802.11b/g network. I noticed that when I'm doing a lot of downloads w/ my 802.11b, the picture/sound is pretty noisy. Note that the Leapfrog (and similar units) and phones use proprietary 2.5 GHz protocols so they don't work cleanly w/ Wifi.
The one here is 5 GHz, which is a little better but you still might have microwave issues. Also, if anyone in your neighborhood uses 802.11a or 802.11n (EWC), you'll get noise on that.
I tried to solve this by using a UHF transmitter that works on channels 2 to 30. But that requries you to have a really good analog tuner and external antennas.
For straight music, I agree w/ Peter's assessment of AirTunes. Granted that means that you have to have a main PC to stream from.
