IMHO, I vastly prefer the TOS Romulans. The TNG --> era Romulans with the bumpy foreheads and 80’s super-shoulderpaddings look just ridiculous. I remember reading that the network specifically wanted the TNG Romulans to have a distinct look from Vulcans, so that “the viewers won’t get confused who are the baddies”.

PIC had both Romulan incarnations and did a great job retconning this by just mentioning the “bumpy forehead northeners” out loud.

Movie/TNG Klingons were an unquestionable upgrade, though.