Many many years ago, I tried to make an argument here on this topic. It was that contemporary JRPGs like Suikoden 2, Xenogears, and some others, might be objectively better than FF7. Man, was that controversial.
The prevalent thought at the time, even through the release of the following Final Fantasy games, was the FF7 was hands down, the best RPG ever. Now it's 2019, and we've seen RPGs come by that make that argument almost impossible. Not because FF7 isn't as great as it was, but because the genre has evolved and you just can't compare the "best ever" of 22 years ago with the "best ever" now.
What do we call an RPG? I think it's pretty obvious we would include both JRPGs and Western RPGs. Action RPGs like Zelda. CRPG used to be a thing: it referred to computer-specific RPGs, which was a style, like Fallout 1 and 2, and more recently Wasteland 2. You never hear of it anymore, but we'll include them. Strategy RPGs were a thing, although I can't think of recent examples. Vandal Hearts and FFT are the classic ones. Include that too. MMORPGs? They won't make my list anyway, so, let's include them.
But what about hybrid games like Red Dead Redemption 2? I would say RDR2 was the best RPG I played in 2018, and I ran around in 1st person with a pistol. Is The Sims an RPG game? You could argue it. I say let's stick to to the traditional sub-genres.
I think my top 5 would be (pretty much in order, but some are very close):
1. Witcher 3. Everything I like about western RPGs, but with a considerably better story than you typically see (it does come at the expense of choice, character creation, and story modification). Also, a MUCH better battle system. I can't imagine making a melee character in Skyrim after experiencing Witcher's combat. Open-world and sandbox style, as is typical in western RPGs, but action-RPG combat, and the whole thing is polished to the point that I think it's the best game we have in the genre. Edit: This game is probably the best example of a western RPG borrowing from the JRPG world.
2. Skyrim. Most hours dedicated to an RPG ever. Maybe even if you included my years with WoW. I don't think I need to expand too much here, but as of its release it was the best RPG I had ever played. Bethesda played a big part in exposing me to the western RPG style with their releases. Combat system could use work, outside of archery which they do really well.
3. Fallout 4. I loved this game. The factions. The sandbox feel with settlement building. The intro before the bombs drop! And for all it's detractors, that story is still vividly remembered. More so than 3. I have played all but New Vegas (in the backlog right now). For whatever reason, considering it's the same engine as Skyrim, the combat seems to work better here. I think it's the tactical aspect of pausing combat with VATS that I liked. See below.
4. Dragon Age: Origins. I loved how this game handled character creation and race selection, (human, dwarf, elf | mage, warrior rogue), and how that would actually completely alter your game start and background story. Almost MMO-like in that regard. I also liked the tactical battle system where you could pause combat, issue a bunch of orders to your party members and queue them, and then unpaused to let it play out. The story was good too; mages were sort of enslaved by the Chantry, a religious group, and if you tried to rebel they basically neutered you, mentally, and you became this robotic thing. Elves were either poor and subservient to humans, or wild and living in the woods. There was so much replay value here. Too bad the series didn't live up. I enjoyed DA: Inquisition, but outside of the Suikoden-like base building aspect, it was inferior overall.
5. Final Fantasy XV. I felt like I was playing a truly modern entry into the series. They incorporated so many western elements that I appreciate. Story was weak I think, because I don't really remember it. But, open world & sandbox game play! Multiple travel methods! Chocobos! And while I like the strategic element of the traditional JRPG action menu and turn-based combat, I just can't help but prefer the Action RPG style you see here. I think the series needed this.
I'm going to have to stop at 5, because if I go to 10 I might end up including WoW which would make me a liar.
What is your "best RPG of all time", as of 2019?