I've been on many rollercoasters.
Some, the less extreme ones that don't have 70'+ drops for more than a meter, nor any loops or corkscrews, are quite fun and provide a nice thrill whilst not being too scary.
Others, the ones with 20+ meter drops at an angle of 70'+, lots of loops and corkscrews, and that jolt all over the place, are not quite so fun and enjoyable. I can stand them, but I hate that initial drop, and don't find them as enjoyable as the less extreme ones.
Personally, I prefer the water ride versions. IDC how steep the drop is or W/E in a water coaster as I'm heading down into water, and its always fun - at least IMO. Especially the ring ones where you and 4-6 other people are stuck in a ring that is spinning whilst going along rapids of some kind, and a few small drops before a giant one. Those are fun.