Action RPGs - games that offer nothing but fast, real-time combat. You kill monsters, collect items, level up, kill bigger and badder monsters, collect better loot. Rinse and repeat. Nothing distracts you from killing, looting, and levelling. Silly things like story and characters won't get in the way of your action. Choices mean "which item compliments this build more". The goal is to make an ultimate killing machine in the chosen class, capable of cutting through anything the game throws at you like a hot knife through butter, achieving the prized "IT'S OVER NINE THOUSAND!" power status.
Story-driven RPG - the focus is on the story. After all those years of killing monsters and looting dungeons for the fun of it, you have a higher purpose, like stopping ancient evil once and for all (or at least until the next sequel) by killing monsters and looting dungeons. While the advantages of having a good story to follow are obvious, stories are restrictive by definition and every now and then the control will be yanked away from the player and handed to the storyteller dude. That’s when you’ll be betrayed, fall in love, will be thrown in jail, do something stupid, decide to travel to the ends of the Earth, gain awesome powers, kill all party members, be defeated even though you are capable of wiping out armies due to an unbalanced combat system, allow your enemies to escape you again, etc. That is the real reason why Aeris died, in case you are wondering. No, it wasn’t your fault, son.