What brand of tools is better Snap-on or Craftsman or Mac or SK-Wayne?

It really comes down to a number of things... your own preferences being among them. I won't use anyone else's ratchets but Snap-On's, for example, but I hate their hammers, and prefer Mac's single piece hammers. A lot of air tools for Mac, Cornwell and Matco are made by Ingersoll, whereas Snap-On makes their own, and some are better, some are not. I'm partial to Mac's "Precision Torque" wrenches vs. anyone else's. My second choice for combination wrenches are the "no slip" ones from Carlysle (a NAPA brand).
Craftsman can be a crap shoot, as their tools have been manufactured by various manufacturers over the years... some better than others. But no way is Craftsman better than Mac.
If you think mechanics have homogenous tool sets exclusive to only one brand, that's the case typically with only the highest paid and most eccentric of mechanics... in my own tool set, I have Snap-On, Mac, Matco, Cornwell, King Tony (KT Pro), Craftsman, SK, Proto, GP, Carlysle, and many others.
For my at-home set, for working on my own stuff... it's mostly from Harbor Freight, although I did choose Carlysle for the ratchets and Craftsman and Husky for the wrenches.
Buying professional grade tools is worthwhile for a professional... if you're doing a bit of shade tree mechanic work, you have no use for anything that expensive.