TTAC3 is part of The Fighting Arts Collective (google that and their new website will come up). Brian runs CQB style scenarios, fun nights and training.
We also run CAPS (practical pistol shooting with airsoft) there.
Brian also runs/owns/hosts games at FTF...and outdoor field by Acton.
C-Q-B.ca (aka CQB) is just south of Bloor and Lansdowne. It's an indoor paintball place. More tactical oriented, larger than TTAC3. I hosts games there about once a month.
Sgt. Splatters is a big sandy warehouse soaked with paint. It smells, it's dirty and more often than not you need to split the evening with paintballers. The owner has a preference for the paintballers (just my own impression).
Defcon has an indoor paintball place (Vic Park and Steeles) and an outdoor field (Downsview). The indoor place is essentially the size of a skating rink with sand. They use paintballs that dry as powder...so no goopy mess, but lots of fine sand particulate. I've heard some very mixed reviews of the outdoor place. Ranging from guys who like it to guys who think it's too exposed and outright dangerous. Haven't been there myself yet.
I think that pretty much it in Toronto. There's other places outside of the GTA. Just keep an eye on the Ontario games forum and check out the location for each one as they pop up.
If you need rental stuff, post up in the particular game thread. Some place required paintball goggles, others don't.