Short version: For anyone not interested in illegally pirating material or doing much work (ie just works), I strongly recommend a Roku or Apple TV. Wired is better than wireless, always. But wireless is probably fine.
Long version:
Currently use about... forty? sixty? Displayport or Mini Displayport adapters. While they are not the devil (aka printers), they are terrible and randomly fail. Yes, we've tried different "respectable" brands. Normally recommend to buy at least two adapters and toss as needed. Average survival is about 9 ish months. Some less, some more. We've bought more expensive models and the lifespan is twice as much for three times the cost.
What we recommend when we can:
http://www.monoprice.com/product?p_id=13370Displayport to HDMI cable. Seems to have slightly better survival interval, but not tested in nearly as large numbers. Much easier to install, much less likely to come undone, much easier to move around when needed.
Having tried all of the media players, I'm sticking with a hardwired Roku box and a Windows 7 PC that runs Kodi. Out in the garage, I rolled my own Android PC (Odroid C2) for playing Kodi. Took a bit of work, not much but it wasn't seemless, and got a very very capable media player that can run any normal Android app. Would highly recommend AppleTV or a hardwired Roku/FireWhatever if you want cheap, fast and excellent quality. Media sticks are near all WiFi and WiFi isn't necessarily your friend when it comes to video.