As hard as it was to not pick The Pass, I went with Show Don't Tell. It's one of their best straight-forward rock songs, and that first blast out of the gate is nothing short of incredible.
I love The Trees, but the title track definitely wins this one. Complex, intricate, and amazingly beautiful, this song (and album) sold me completely on Rush as a band, rather than just 2112.
This is probably the hardest choice out of all of the albums. The title track, Xanadu, and Cygnus X-1 are all among my favorite Rush songs, but I went with Cygnus for Alex's amazing solo. It leaves me awe-struck everytime.
Don't feel much need to explain for this one, but since I'm posting in all of the other ones, I might as well
2112. For obvious reasons.
Although, as a kid, I always loved Twilight Zone. The whisper track freaked me out.
I went with Force Ten (I first heard the live version on R30 and fell in love with it right away), but Turn The Page is a close second. Time Stand Still is great too, of course.