The choice depends on your specific circumstances and what you need to do with the connection.
How densely populated is the area around you -- lots of wireless users or none? You can get some idea with the free home version of inSSIDer from
HERE.
Are you gaming, streaming video, or just checking Facebook and email? Uses matter. Streaming video takes a lot of bandwidth and gaming likes low latency.
Powerline or wireless work in the right circumstances. I've used the Zyxel PLA5205kit and PLA5215 kit and would recommend them highly, but I've also used a pair of ASUS RT-AC66U, one in router mode and the other in media bridge and they work quite well too. ANd of course, a cable is always the best if it is possible.