What’s better quality for movies?

Whatever format allows you to view the entire frame of the film.

Generally speaking

"full frame" refers to pre-HDTV television

- i.e. standard definition television

and to very old movies that also had that same 4:3 ratio.

Widescreen refers to most movies since the 50's

and to HDTV

and generally speaking

widescreen movies were more popular than full frame movies

and of course HDTV provides much higher resolutions than did SDTV

and so

in general

widescreen provides superior entertainment.

140p was the best