Depends what you want it for. I've used wireless HDMI products from IOGear and Air3C. I prefer the Air3C, but the IOGear can go through walls much better, and can output to 2 devices at the same time. I didn't need that, but you might. The IOGear uses WHDI, which causes compression artifacts around text, but the Air3C uses WirelessHD and doesn't do that most of the time. It doesn't have to have line of sight (it bounces the signal off walls) but it will perform better if it has it.
I have a couple of posts in the another thread here and here that document my experiences with Wilress HDMI.