I went to theatre school, so a bunch of people I know rather well have ended up... somewhat famous? It's weird because they aren't actually famous, but I see people I know in ads and commercials all the time, like this one:
Geoff Gustafson was a good friend at school, he's been in a bunch of other commercials too and apparently was in The Interview and Hot Tub Time Machine, neither of which I've seen. :
The others who have gained the most fame are probably
Erin Karpluk, who was the lead in Being Erica on CBC; and
Thomas Middleditch who was Richard on Silicon Valley and had small roles in Wolf of Wall Street and The Campaign.
One of my ex girlfriends very nearly played a prostitute in
The Assassination of Jesse James, she's had some success in Calgary theatre and was on the radio for a while.
One of my friends has won a couple of Emmys for production and another buddy edits together the montages of films for the Oscars.