My dad's been going to Sam's for over 20 years, ever since he bought one of the first Saab's in Canada and couldn't find a mechanic who could service it (until he met Sam that is). I've been going here since i got my first car. We live in North York and drive a half hour to take all our cars here. He gets really busy around the time when people are swapping tires (beginning and end of winter), but otherwise if you call ahead they'll tell you a good time to come in.
The only mechanic where i drop my car off and ask him to do whatever needs doing, and not worry about being ripped off.
We've bought most of our used cars on their recommendation too, mainly because we trust any car that they have all the service records for. Prices have all been reasonable, and they have a preference for Pirelli tires (because they love them).
There's always expensive cars in the parking lot (as well as police cruisers). I mean that says a lot of the cops go there to service their cars.