Depends on how you define "best".
Theres the Fitness World chain which is upscale, expensive, good and kinda cruizy too in certain locations.
The best value for money is definitely geting a 45 dollar flexipass from the VPB, gets you unlimited access to all gyms and pools across the city. That's what i do.
But I don't know in what part of town you're at. There's also the brand new Y which looks really cool (haven't been inside there myself though)