I just remember how this game traumatized me as a kid by the horrible scary stuff it has at some points! So here's my top 5.
1) Being scared shitless by that mofo warlock on top of the wall shooting those creepy scary skullface homing missiles that would come after me and make that horrible, horrible scary sound!
And FINALLY after many weeks of playing finding a way to get up the wall and killing the son of a bitch that terrorized me for so long!
2) Holy shit, stone ball rolling down the corridor, noes! *Runs away* *BAM floor collapses* *ends up in a pit full of skeletons*
3) Opening that damn door with the lever in the underground part behind the waterfall in Elmore's Retreat I think (not sure which mission) and having that freaking Gargoyle standing right on the other side. *HISSSSS!*
4) I farmed the first map of Destruction extensively and there are those wraiths in the castle. One of them is in an apparantly dead-end room. So I was doing that map as usual, entered that room to kill the wraith, but it wasn't there. So I thought whatever, and continued. After I walked down the corridor further, suddenly the sucker was right behind me. *HISSSSSS!* I realized later that that 'room' was actually a shaft and that the critter must have flown upwards a bit, where I couldn't see it, and came down again as soon as I opened the door, and pursued me! Evil game!
5) Temple of Astarte wraith room teleport after trying to steal the treasure. Surviving and then getting blasted from afar by the evil wizard himself.