I watched a fair amount of Star Trek: The Next Generation and I have to admit I am firmly in the "never-noticed" camp regarding the way in which Riker sits down. Yet there it is, sitting in front of us the whole time:
The comment thread in the linked article is both entertaining and informative; apparently the original uniforms were, shall we say, not man-friendly, resulting in the act of taking a seat becoming a roll of the dice. Shall we say.
H/t Christian Ready's FB page.