Adventuring Party! The simple "Party Game" RPG
"Adventuring Party!" is a "Party Game" style RPG. Its a good intro RPG as it handles standard fairytale and pulp adventure, its got solid mechanical choices built in (there isn't just one way to handle things) and can be learned, played (including character creation and building an adventure) in an hour.
Adventuring Party uses a roll-and-keep/dice pool mechanic for task and conflict resolution. The instigator of the action rolls a pool of dice equal to the appropriate ability score plus their level, keeping a set of "n of a kind" or a run of three or more. The instigator's chosen dice become the target for the opposing roll.