I was a big fan of these first-person dungeon crawlers, though I was horribly lost playing them on my brothers Commodore 64 (he kept the manuals hidden from me as a deterrant). I did rent many of them on NES (again, no manuals made it rougher than it had to be). It was not great fun for me early on but I either figured out what needed to be done or had a friend that had the game too and I could read their manual during lunch at school.

One game I fell in love with on the C64 was Alternate Reality: The Dungeon. No manual really needed for this one. It is brutal as can be as far as tough, but it is a great "introduction" role-playing game for anyone wanting to get into these games without all the levels of spells and power of that spell complicating the fun.

Swords and Serpents on NES is an even better introduction to this genre. Also Arcana on SNES is a great intro title for anyone interested.

I can't wait to read your thoughts on the later Might and Magic games, World of Xeen is quite a bit of fun.