I'm not sure what ones I got first, but I didn't have that many when I was young. Of course, I thought I had tons, but now I realize it wasn't that much, really.
Here's the list:
6039 (Twin-Arm Launcher, 1988)
6060 (Knight’s Challenge, 1989)
6077-2 (Forestmen’s River Fortress, 1989)
6085 (Black Monarch’s Castle, 1988) -- TWO copies
6016 (Knight’s Arsenal, 1987)
I didn't realize I had two copies of the Black Monarch's Castle until I broke out my old legos last summer. (Oh yes, I said "legos", plural -- deal with it!)
My favorite was the Knight's Arsenal, because it had wheels and a way to harness a cart to a horse, and I spent most of my youth devising ever-fancier carts for that horse to pull.
I've also "inherited" (a.k.a. stolen) my sibling's sets, so I have one that had a ghost in it.... oh, I so coveted that ghost when I was young, and my sister had it, and she just didn't appreciate it.
Since I've been looking at my old sets and minifigs, I've come to realize I know just about NOTHING about the various factions. I didn't even know there were good guys and bad guys till this year; it all went over my head when I was younger. I'm still not that interested in factions, but I feel I ought to at least become more educated about them. I guess I'll have to do a bit of research.