This is one of the best, if not the best, Klondike games I've come across. And it's free! It's fast, the opengl effects are smooth, and plenty of options to set up the game's appearance the way you want. For example, if some of the various effects seem too much, just turn them off. (I did) And No built-in restrictions or limitations, just play away.
For basic Klondike, I never found anything all that great for the Mac. This software is just unbeatable. The only suggestion I would have to improve upon it is an option to display a dialog when you run out of playable cards to win the game, instead of having to figure that out the old-fashioned way.