CZ 75 is a pleasure to hold.
My G20 is not great but I can hold it a lot better than my L frame square butt S&W.
Those new wooden grips sure are pretty but they made them thick as a mofo for whatever reason.
Most uncomfortable: Any stock hunting rifle with those cheap plastic stocks.
Most comfortable: Any rifle with a manners adjustable stock.
Handguns, made the mistake of getting my brother a glock 19. He likes it, but to me its front end heavy, bulky, and hard to grip. My 17 and 34 are much easier to handle pistols.