The D7100, because you'll never need another camera, unless you have special demands or you're well beyond the 5 year limit of useage of a digital camera.
The D5300 is a not too bad choice too, because of the swivel screen, the lesser weight and smaller size, and IIRC it also has WiFi, which opens new possibilities.
I frankly have no friggin clue why the D3300 exists.
If you're a true masochist, yes.
Digital cameras allow you to take pictures basically for free, review your results instantly, and to photograph in situations in which film cameras are an extreme hassle.
My first camera was a film camera. You know how many photos I shot ? A total of zero photos. Why ? Because it was an insane hassle and I didnt had the nerve.
a manual film camera !! For the modern times, so painful, expensive and time consuming to learn
You forgot to point out SLOW. It can take days and weeks to get your film developed. And to get film in the first place and transport it and having to change it every 38 or so exposures.
I would say a D80 or D90.
Those are pretty old. Dunno about the D80, but the D90 I've handled and yes its a good camera, too.
Buy the best camera you can comfortably afford (and keep in mind, leave some room for money for lenses).
I used that strategy and ended up spending a lot more than I would have, had I just bought a really good camera in the first place.
After spending about 3k€ on various compact, bridge and entry level DSLRs I went all "wtf are you doing, you spend this much money and what do you have to show for it ?"