The Almighty Old Skool Clasp...

Hook & Beak, Pressure Fit, whatever you want to call it...

as I own, see, use more watches, and by proxy clasps, the more I am starting to think the perfect clasp is one where you snap it down (or even snap it down and then have a latch over that to ensure against accidental pop-ups via snags... ex: the Rolex Osyterlock), lift it up to release it and it has multiple options for wrist expansion/contraction via either inner indentations or drilled holes.

I've seen/heard many examples of clasps with pushers failing and freezing... and even though I have yet to encounter such an issue I will say that my OEM clasps on Omegas that utilize pushers, over time and with daily use, start to feel - for lack of a better term - sus and jenky whereas my watches with Uncle Seiko and Rolex clasps feel and work flawlessly.
Caveat~ not a Rawlexx fanboi here at all... I own two of them and barely if ever wear them but I do love their clasps more than I could ever love a human baby (all props to Chaz Michael Michaels ~ Blades of Glory).

I dislike butterfly clasps in general (just a personal thing for me) but even they are superior in feel to a pusher to my mind.

What are your thoughts on the perfect (or imperfect) clasp?

I am a big fan of Omega's milled clasps. I first encountered one in 2005 when I bought my Seamaster Pro 2551.80. I thought it was a very good design. Very robust and highly unlikely to accidentally come undone. I previously wore a Tag Heuer that had a press clasp with overlock, and that was starting to feel very loose towards the end. Even with the overlock it felt as if it could still come undone. Touch wood I've never had the Omega clasp fail on me once, and it still feels as good as the day I bought it. If there's room for improvement, it would be the inclusion of a micro adjust mechanism for hot days. Also, it's a scratch magnet but I'm willing to forgive that.