Good old DungeonQuest. Originally a Norwegen game, it made its breakout in 1987 when Games Workshop picked it up and released it in the UK and North America. It fell out of print somewhere in the '90s and lay dormant until Fantasy Flight Games relicensed it in 2010.

Unfortunately, FFG messed with the combat system and made it over-complicated and slow. Thankfully FFG did listen to its fans and now we have DungeonQuest Revised! Basically, they took out all of their changes.

Those of you who are not familiar with DungeonQuest, here is a quick rundown: 1-4 players are sneaking into Dragon Fire Castle to steal some of the dragon's sweet golden loot. Whoever escapes the dungeon with the most loot wins. The map of the dungeon starts as a blank grid with the dragon's treasure chamber into the center. Every turn a player explores a space and adds a room tile or two to the map.
The players must overcome many kinds of obstacles in their quest of gold: traps, moving corridors, and monsters. All while racing against the sun. If the sun sets and you are still inside Dragon Fire Castle, you lose. Once (if) you reach the treasure chamber it's time to grab all you can. If you disturb the sleeping dragon...it will go poorly. Then simply (not really) find your way back out before sunset.

It is a random and often times brutal game. Many times the "winner" was the hero who died last. Having all four adventurers get killed is not uncommon, which is why when we play it two-player we each take two each.
 
The game is up to FFGs excellent standards for components, and has just had a reprinting. The game sets up quick and plays very fast, with each game taking around 45 minutes. Highly recommended for when you are in the mood for some light, fast gaming. Just don't get too attached to your characters.  

Go Roll Some Dice
And Try not To Wake the Dragon