Define "RPG".
Role Playing Game. Basically a game where you play a character which you create using a set of rules for combat and social interaction. That is by the way what real RPG are anyway, be it pen and paper or pc based.
I don't need to tell that in P&P the freedom and storyline is limited to imagination of players, although a gamemaster may limit that by guiding players back to his planned storyline if they stray too far.
Pc games that get closest to the roleplay element are the ones that have an open world, have a set of rules for skill usage, have a main storyline, yet do not restrict a player to it, have a stat improvement element and should have a bunch of side quests to give the illusion of the freedom the P&P actually have.
Many games have more or less of those things, for me the one that has most of them is the "truest" RPG. For example Elder scrolls games are all sandbox games and have stat buiding, but they are controlled like FPS which make them less "playing a role of your character" and more "take direct control of him and use your own reaction skills". On other hand games like Icewind Dale and Fallout Tactics have stat building and is oriented around combat neglecting the social aspect making them tactical games rather then RPG.
Ofcourse you have that piece of stinking shit of Japanese games made obviosly in a society of little free thinking, making you follow a narrow path, slaying many things containing only one fucking element of the RPG which is stat building and a few dialog option which will lead you to nothing other then one result anyway.
I mean when i look up RPG on GameFAQs i do see Baldur's Gate, Aion, Diablo 1,2 &3, Dragon Age, Fable and so forth- but that doesn't stick in the classic RPG category with me 
As I already strongly hinted in a post above this quote: Eat shit and die.