To me still the one live-action Superman TV series I can sit through any episode of. The fact that it's only a half-hour long probably helps; I've never done well with hour-long genre shows outside of Trek TOS. What it lacks in Superman mythos, IMO it makes up for with a great cast that put their best into the roles no matter how kiddie it might have seemed, especially during the color years.
My favorite episode to this day remains "Five Minutes To Doom". It not only predates STAS' "The Late Mr. Kent" by forty-some years, it also showcases Jack Larson's Jimmy being a comic relief but with a definite purpose relative to the plot (trying to distract the builder as a vacuum cleaner salesman so that he can abscond critical evidence of foul play from the scene); it also shows the Daily Planet at their best investigative selves (which is another thing I REALLY like about TAOS - for lack of pure comic-book villainy which they clearly couldn't afford, they compensated by playing up the newspaper/reporter aspect of Clark/Superman). Heck, we even get to see that Superman's trunks actually have a function besides just an aesthetic one (by serving as a big wraparound 'pocket' that he can stash the Governor's written pardon in as he races to the Big House at breakneck speed)