Original Carmageddon! http://www.gog.com/game/carmageddon_max_pack
If you are into this sort of thing.. Automation. http://store.steampowered.com/app/293760/ Except in it's current state you kinda want to find it on sale.
I imagine you Calgarians would like World of Guns: http://store.steampowered.com/app/262410/
Deus Ex: Human Revolution if you haven't played it is great, same with the latest Tomb Raider reboot, Just Cause 2 can also be a lot of fun. Outside of that I'm not 100% sure as most of the games I play PC are all multiplayer/mmo I use console for single player games seeing I didn't like the old DRM policies back in the day and have mostly stuck with those for single player.