I'm not a professional film reviewer like you are, but I think the fact that Highlander is "damned entertaining" is exactly what makes it a "good film." I mean, it is a film about immortals, so going to the film looking for deep analysis of the human condition is going to leave you disappointed.

That being said, the "Stabbing myself => foreplay" is a bit unbelievable, which is how I judge whether a film is good. I'll also note that the extended version adds some deleted scenes that make the rest of the film better.

Apropos Queen: After my original comment I wondered if part of the fact that I loved the film is because I was (and still am) a huge Queen fan. IIRC, their cover of "New York, New York" does NOT appear on the soundtrack and Queen refused to ever play it again (Sam) on either an album or live.

Back to "what makes a film good." The Kurgan was a huge, physically powerful, and more than a bit clever immortal. He's roughly 3000 years old, with basically no conscience to speak of and he knew he was the strongest of the immortals. Back in pre-internet days, he could remain untraceable. So the Kurgan was basically a god. If power corrupts, and absolute power corrupts absolutely, Clancy Brown's Kurgan was about what you could expect, in that world.

Your mileage may vary...