Michael Curtis, of the Society of Torch, Pole and Rope, has a post about the random dungeon chart from the old TSR Indiana Jones game here.
I really like it. As Mr. Curtis himself says, it's good for making a dungeon with more thinking, less fighting.
It also utilizes something I was trying to do when constructing my megadungeon (before my players uniformly stated that a megadungeon was the last thing they wanted and I shelved the project), which is encounter areas that show signs that other adventurers have been through.
I had empty treasure chests (sometimes with calling cards of who looted it), corpses in various states of decay and having met various foul ends, notes and journals, marks on the walls, and one thing I thought was really important to get that immediate feel of others adventuring--spells with durations still in effect when the PCs get there (that one actually works well on a random encounter table, too).
Anyway, I copied that list, and plan to use it to good effect in the future. I suggest you do, too!