Re: You forgot one important(sic) catagory
The Human face is far more suited to a 4:3 (or similar) aspect ratio.
Been thinking about this as I'm watching a lot of older shows with a friend (stuff like Hogan's Heroes, Mash, U.N.C.L.E to name a small few). 4:3 works well where you're more inclined to be up close on a person's face. Mash and HH took place largely indoors in confined spaces, so there really was no use for widescreen formats. Even a lot of UNCLE and other shows (Mission Impossible (the real one not the cruisewreck) and probably even Space99 (yet to start so not sure) were based on small areas (like a small room) where there was bugger all point in going to widescreen.
A person's focus is something like 3degrees off centre. With a widescreen, especially when one character is focused, you get a lot of "wasted" space for most people (course, people who let their eyes wander are looking at the background in more depth). I think for much stuff 4:3 is ideal, while 16:9 can show off a nice panorama.
That said, when I had it I loved my 16:9 tablet, mainly for the ability to use it in portrait mode and read.