Adam West was fairly nice and easy-going. It was the mid-90’s when I got his autograph, and he posed for pictures with people who bought autographs. He let the pretty girls hug him. He didn’t do the hover-hand thing, but wasn’t lecherous either. That’s just what I saw in the 5 minutes or so I was close enough to see what was happening.
Dave Prowse talked with my girlfriend and I at length, as nobody was lining up. He had just set up, and it wasn’t terribly clear who he was. I asked a con worker where he was, and she pointed at him. I said, “That can’t be him. Dave Prowse is like 4 inches taller than me, and that guy’s my size.” She then told me about his arthritis issues.
I have some sympathy for him. He took the role as Vader not knowing his voice wouldn’t be used. Imagine being a little-known actor who has a huge role in a blockbuster film, and no one ever sees your face, and then they edit out your voice as well. He probably felt minimized, and cheated out of the opportunity to parlay that into better things. That, and his failing health, probably caused him great bouts of depression.
Prowse told me he was very appreciative of Kubrick giving him his break in A Clockwork Orange. I was able to talk to him about that, and his small role in the BBC TV version of The Hitchhiker’s Guide to the Galaxy, and of course, Star Wars. After a few minutes, and having been entirely unprepared to have that kind of access, I ran out of things to talk about. My GF and I said our goodbyes, leaving him to sit with his convention handler.
(signed cast picture of Night of the Living Dead) I guess it’s too late to ask for it back, huh? 
In some ways, I think it’s a little crass and intrusive, but in other ways, you get a moment to meet someone who’s brought joy to your life and let them know it, and you have a memento of that meeting. In retrospect, I have almost entirely pleasant memories from it.