Good choice on the Pirc. That is the system I use as black on chess.com. Generally, the same moves work against 1. d4 and 1. c4 (in those cases it'd be the King's Indian Defence) as usually the opponent will play e4 at some point, transposing. In this way, I only need to know one opening as black.
Here are some games where World Champions got beaten by the Pirc:
(Sorry, there's a lack of annotation)
http://blog.chess.com/Nytik/pulling-off-the-pirc
At the moment, I haven't really decided on any openings, I'm largely going with "classical" openings such as Spanish, semi-slav etc, but my knowledge on these lines are all shallow, and I usually just play logical moves and try to activate my material.
However, I'm now getting interested in starting to look into the openings, not focus my studying solely on it ofcourse, but start to look into them. The opening (defence) that has cought my interest the most, as black, is The Pirc, it seems to lead to dynamic games with both tactical and strategical positions, and it's something I want to give a try.
But, I have no idea what other defences and openings to use, I'm thinking the Slav/Semi-slav against 1.d4 and reversed Sicilian against 1. c4. But these are far from The Pirc, and I only play them since they seem logical. What other openings/defences would go well with the pirc, that are still reasonably sound?