I have a fondness for the old Keep on the Borderlands. One of my earliest D&D experiences in the early 80s was being a 4th grader watching 5th graders play this in the school library, and it was fascinating. The stirges were deadly, and the Mound of the Lizard Men was like a beaver dam with an underwater entry, which was fascinating to me as a 9-year old. The trapped goblin caves and the minotaur cave was scary and awesome. The obnoxious Thief picked a lock on a chest and the DM described a small living crystal statue unfolding from the chest and blasting the heroes with crystal shards before they shattered it. (I learned later that the DM added some of his own stuff which showed me you can make an adventure your own.) The way I look at it, it was my first watching of a live-play.
I never got to play with that group (I was a year younger, and was therefore too young), but I never forgot it. I picked up the adventure at a later date and scoured through it for fun. I ran it several times throughout the years, once was as the alternate beginning of the Night Below campaign, and we always had a good time.
I'm looking forward to this version. The adventure is what you make of it.