I have a pair of Sennhieser RS-120 RF wireless headphones and I love them. I use them constantly. I like the fact that they are RF and there are no line of site problems. I get very little interference in my house and they literally have a 300ft range. Of course, there is the occassional pop of static when you get farther from the transmitter but overal it they are excellent. The charging cradel is genious. It is very easy to use unlike many of the chargers out there (especially Sony's). I have never had the batteries die, even after 15+ hours of use. Sound quality is very good.
The next step up from mine are the
RS-140's. I have heard them and they are an improvement over the 120's. I like the earpads better on the 140s as they enclose the ear instead of sit on top.
If you simply cannot stand any hint of FM interference then you would be a good candidate for and IR set. The main problem with IR is that you need to be in the line of site of the transmitter. Another option would be the
AKG Hearo 999 digital UHF heaphones. They are a bit pricey, however.
I would not recommend Sony wireless phones after listening myself and hearing what others have to say about them.