Just like some people already in this thread, I would like to see much fewer combat encounters, and every encounter should have a reason to exist: resolving a conflict between a character's motivation and an obstacle. +100XP and trash loot is not a good reason. Really, it's gotten so bad that nowadays RPG's have to include a trash management system in character inventory.
The combat should also be more tactical. Ideally, in a party based RPG the player should act more like a commander of a unit than like a weird puppetmaster that is "ASSUMING DIRECT CONTROL" of one guy at a time, leaving the other characters to run like headless chicken in the meantime. Imagine if you could position the characters, then assign orders and see them executed to the character's abilities.
I would also love to have more non-combat skills that are useful in interactions with NPCs and environment. This has been getting a bit better in the recent years, with dialogue checks and systems like environment checks (Pillars, Tyranny). The new Torment also promises some kind of non-combat Crises.
Finally, it would be great to see settings and stories that are either more realistic and believable, or more inventive and alien. Too many RPG's these days tend to stick to common boring tropes and weak attempts at humor. To give some examples, I think that Arcanum, King of Dragon Pass, Fallout 1, Morrowind, Pathologic, Eisenwald all got it more or less right. On the other hand, Tyranny, Dragon Age, Divinity Original Sin, Oblivion, Fallout 3-4 got it wrong. Although some of them are good games in other regards.