I did a cheap whiskey comparison where I bought two brands at once and the winner continued on to face the next challenger. I ended up with Grants from Scotland mostly because it was the smoothest. Fortycreek stands out in my memory as the harshest I tried, Crown Royal was second choice.
Free is always good too, and after a few brews with the boys I like the real smokey stuff like Laphroaig, but I have a hard time dropping that kind of money on a bottle regularly...