I know what you mean... Movies that I saw that when I was little that scared the willies out of me, though I haven't seen them since... I am fairly certain that I would find them cheesy and not very scary, which is why I don't want to see them today...
"Valley of Gawangi," about some cowboys who venture into a lost valley to bring dinosaurs back for a circus or something, "Day of the Triffids" which scared the willies out of me, and made me want to live in a submarine are just two that come to mind off-hand.
Mark
"The Valley of Gwangi" starring James Franciscus. Great movie, actually. A personal favorite.
Saw the previews for that one in a theater as a little kid and it completely freaked me out. There was just......something about skulls.......scary as hell.
Of course, saw this stinker years later on TV and it was pathetically bad. Laughs, groans aplenty.