I agree with Karlos, on Amiga Os 3.X, how could anyone vote for a Mac OS, I get nausea just thinking about Mac OS, you really have to be a diseased person to even touch a Mac. I made a mistake once and bought a Mac, lucky thing I had hazardous material training in the Navy and still had my old suit, wouldn't of touched that mini mac any other way. Threw it out in the street once and someone threw it through my truck window, saying how day I throw this junk out in the street. Left it on a street corner saying free for the taking, and someone called the police and said I was contaminating the city, had to take it back in the house. Lucky thing I had my hazard suit or else the police would of made me go to the hospital for a checkup.
My second best GUI is Linux, using Zorin 8.0, looks and feels like windows, but doesn't crash and works. It now takes care of all my important stuff, like how many dollars I have, doesn't have to work to hard in this category though, it always reads 0, LOL.
Have fun and don't contaminate the U.S. don't buy a Mac, Apple, or whatever. Windows is better then Mac's, Windows only crash twice a year, Mac's just die, and at their price, well you know.