TOS is unaccessible to those who crave the visual over the story (a lot of modern audiences, sadly). As a rule, I've always said that if you don't like seeing plays at the theater, you probably won't like TOS
TOS does have some great action episode, mind, which look even better with the new Remastered boxed sets (CGI replaces the iffy 1960s effects...which were kind of cheap in their day, too). 'Balance of Terror', 'Arena', 'The Doomsday Machine', 'The Ultimate Computer', 'Amok Time', 'Mirror, Mirror' and 'Court Martial' are all favourites of mine that are light on the sci-fi and heavy on the action/drama (though I obviously have other favourites that are heavier on the sci-fi). Probably easier as jump-in points.