My boyfriend, as soon as he spawned on the generic sand, dug down 20 meters and hit a huge cave (but no branches) filled with goodies like iron, coal, gold, redstone... you name it! Everything except diamond.
Btw, he knew nothing about mineral depths, F3 (ah, the magic of it), X-ray packs, etc etc.
As an added bonus, there wasn't a single hostile mob in there. Is this even possible? Hmm...
Anyways, does anyone have had a similar experience? Except for sub-surface dungeons : D