Which is the higher quality of three export modes?

Web hosting? Computer? Apple Devices?
Apple devices looks great to me already but maybe i just have peasant/nonprofessional eyes lol. what will look better on more devices, on more displays? (apple devices is tempting because its smaller files too)
i guess i could take the time to export the same video in all three formats

Depends on what your target display is. Each of those is tweaked for the specific medium they are targeted for. One-size-fits-all isn't really something I would recommend looking for.

Basically, go for H.264 and tweak for the medium you're going to show it on.

well im going to put it on youtube for viewing on mobile devices and computers and pretty much everything

I use Master File, set it to Video And Audio, H.264 and get great results.
If you want to technically have the very best quality possible, export as ProRes 422.