Please take Toronto out of the equation first of all.
In terms of Cali and NY, it really depends on what part you're gonna go to and what atmosphere you like. NYC and the surrounding cities are wonderful enviroments--the people, places you can visit, it's just live all the time. With LA, and I hate to admit this because I've been such a West Coast hater for years, almost everywhere on the coast of Cali is beautiful. The scenery, the weather, the women, etc.