I know that all Oscar's are the wet dog aquarium pet, and hearing from what others have said about JD's in this post mine is completely the opposite, he is always coming to the glass whenever I come near and very interactive. I also have a featherfin in there and he kinda tells the others to get outta his cave when he wants his alone time, but otherwise no aggresion in the least more curious than aggressive.
MY GT is very "Personable" but I bought him at 4-5" and he stood out in a 150 at the lfs with 5 JD's and 3 other GT's in it along with 2 of the biggest Oscars I've ever seen
If you're looking for a personable fish look at lots of them, then you'll be able to make a better guess. I'd look at JD's and GT's though whenever you have the chance
I'm not a big Oscar guy. They seem fat, slow, and boring, to me but many folks here love em.