Mypick would be 'How it is' from Vapor Trails. I also reckon it's their best song of the last decade too. The bass part is insistent and driving, yet in the bridge and chorus it backs off and does a wonderful counterpart to the vocal melody. Geddy is really pushing the whole song along, backed by beautiful guitar and drums. If Geddy insists on the flamenco parts, they should be like this.
Sadly, although I still love Rush and I enjoy their current output, their music has become a little bit simple. Maybe it's a hangover from Counterparts. They embraced the heavy rock sound on that record and left behind the beautifully arranged, melodic style they had perfected with Hold Your Fire. Since then, they've not got that back. I want Rush to sit down and talk about arranging something, a song that is lengthy and intricate and beautiful. They can still knock out a good riff, but I long for the 'old' Rush, who would write a song that was both catchy and engaging but also very deep, rewarding repeated listens.
http://www.youtube.com/watch?v=6IDqj0YYa9g