I didn't know about Matthew Perry! (Just watched "Fools Rush In" again last night.)
Then there's William Shatner too. And Lorne Greene.
My mom watches the ABC show "Castle" with Nathan Fillion - he is Canadian. Blackhawks captain Jonathan Toews is Canadian (and many other Blackhawks players are too ... Crawford, Bolland, Bickell...).
And Gary Sinise ... he's not Canadian- he's from Chicago ;) (Sorry, I had to put one in!)
I knew about Alex Trebek. Canadian of Ukrainian descent. I'm convinced that each episode of Jeopardy! has one or more Canada references in tribute to his home country.:D