Leveling Up

That's one of my favorite things in the RPG genre. Most of the times it needs lots of time and patience. The player also has to find the best place to level up at that specific moment, forcing him to use his judgement.

Resource Management

A good RPG is one that forces the player to choose when to buy a specific item or equipment. It's better to save money for that awesome sword or spend it all at once for that good shield ? That's the kind of choices that make an RPG interesting to me

Character Customization

It's a fundamental part for me in enjoying an RPG. For this reason, one of the things that frustrate me the most is what I call "Fake Customization". This is how I call it when the game gives you the chance to customize/upgrade the character(s) the way you want, but it eventually forces you to use a specific spell or skill to defeat a boss and advance.... over and over and over.

A good way to do that, it's to give bosses and enemies different weaknesses for the player to discover - or just to make a boss a bit more difficult but not necessarily unbeatable if you decide to use a different tactic than the one you're supposed to use. "Fake Customization" is even more amplified when the game forces you to employ a specific character in your party every time a boss or mini-boss appears.

Choose Your Heroes

I like to choose my "main characters" when possible and stick with them for all the game. For this reason, I find difficult to enjoy those RPGs where your party members are changed by the game all the time. This is one negative thing that is abused quite a bit in many RPGs, one noticeable example is Final Fantasy IV.