How are these props/non-human characters/vehicles for instant recognition by the multi-generational, multi-national public, because they were unique and exclusive to one film, show, or character:
* The Nautilus from 20,000 Leagues Under the Sea (do vehicles count?)
* The H.G. Wells Time Machine from the Rod Taylor version
* T-800 Endoskeleton (do cyborgs count?)
* Gort (do robots count?)
* TMA-1 "The Monolith" from 2001
* Smith & Wesson Model 29 .44 Magnum (i.e., "Are you feeling lucky, PUNK???")
* Wilson!!!!!!!!
* Maria from Metropolis
* R2-D2
* Darth Vader's helm
* The U.S.S. Enterprise NCC-1701
* Spock's ears
* A Tribble
* The '66 Batmobile
* The Trojan Rabbit from Monty Python and the Holy Grail
* Rambo's combat Bowie knives in all their versions
* Bruce the shark
* Devil's Tower ("yeah, I've got one in my living room...")
* Masks of Zorro or the Lone Ranger
* Master Yoda
* The One Ring
* Patton's Chrome helmet
* The knife from Psycho
* The Phantom of the Opera's mask
* The Little Tramp's hat, cane, and shoes
* The pumpkin carriage & glass slipper (do animated classic props count?)
* Godzilla suit
* M-203 (M16 with 40 mm grenade launcher) from Scarface ("say che-llo to my leetel friend!")
* Flash Gordon's ray-gun
Too tired to come up with more, but you get the point.

Bottom line, even if a non-collector doesn't recognize any of these right off the bat, good chance he or she would get them right if they appeared on a multiple choice test!
Regarding some of the others mentioned, I think Luke's lightsaber is probably the most iconic SCI-FI prop ever and No. 1 on the wish list of every young boy (still is on mine at 42, lol!), but only when the blade is SWITCHED ON - I doubt most people who are not prop collectors or hardcore SW fans would recognize any of the hilts for what they are. I also wouldn't count the Ten Commandment tablets because they are HISTORICALLY recognizable, and in many forms - I'm not convinced even someone who's seen the film would be able to pick the screen-used set out of a line-up of other full-scale tablets.
P.S. - great way to introduce myself, don't you guys think? :angel