Skyrim may well be the defining game of the 7th console generation. Aside from the massive sales, comical number of ports, dank memes and stellar review scores, certain design choices first introduced in Oblivion and then honed and perfected in Skyrim are nearly inescapable in today's open-world games.
If you were able to go back in time to the 2D era and show someone a single game that reflects what the gaming industry writ large has become, you could do a lot worse than picking Skyrim.
All that being said, I've always much preferred Morrowind to either sequel. If I'm suddenly hit by the urge to jump back into Tamriel, it's more likely that I'll be landing in Seyda Neen rather than Helgen or the Imperial dungeons. While I can certainly recognize that Skyrim is a significantly more polished, successful product (Oblivion is the black sheep of the franchise in my opinion, redeemed only by the stellar Dinner Guest quest), there's something that keeps drawing me back to Vvardenfell.