Tokyo Sushibar on Saint-Paul (not to be confused with Tokyo Sushi on Saint-Catherine street) is one of my favourite sushi places in Montreal (and I've tried many). They have very creative rolls with unusual ingredients. Try the specialty rolls, they're worth it. Yum! My eyes are usually bigger than my stomach, and I always leave stuffed.
The wine list isn't terribly extensive or interesting, but you can find a nice, drinkable white for dinner. Service is decent. They also offer a reasonably-priced lunch special, and do takeout. Like J.F. mentioned, it's best to reserve ahead for lunch because it fills up with the Old Montreal office crowd. It's a little quieter in the evenings.