Some may argue that Fallout or FF beats it, but I think not. The beauty of Skyrim stunned me. I now know that I didn't regret spending $60 on it and I think it deserves so. If your a die hard FF fan, fine. Say what you will, I'm interested in what you will say.
I have found that the game play is better than any other game. I have played lots of other games but Skyrim is by far the best RPG and it has still kept me interested even after having beat the campaign twice. There are always different choices to make and different paths to take that make it the best.
For just Western RPGs, Fallout is like you said a strong rival. Elder Scrolls isn't conclusively better. If you add in Eastern RPGs, Persona and Shin Megami Tensei are also great. If you're indeed looking at "ever," though, you have to look to the past too. There were some great RPGs released in the 16-bit era that have aged impressively. Already, "realistic" graphics from the 6th/early 7th gen are getting dated, yet the graphics, plots, music and combat of games like Secret of Mana, Super Mario RPG and Chrono Trigger remain as stunning as ever. So the greatest RPG ever might not even be a current one.
In comparison to most RPGs, Skyrim has been watered down for the lowest common denominator of gamer. Not only is this simply not admirable, it also makes the game a less rewarding experience. It is just so much easier than a game like Fallout, and thus I feel less rewarded when I get something done in Skyrim.