IMO, it's the forces of nature that make games really worth playing. I'm not a huge NFL fan or anything, but when I see a game being played mid-winter in Greenbay with snow falling, and I know everybody up there is freezing their asses off, it just makes the game wayyyyy more fun to watch. Within reason of course. If shit looks dangerous to the players or crowd then it's definitely time to call it off.
I also give props to those teams out there that still use natural grass for their fields, and reject the NFL's pressure to switch to artificial turf.