The Elder Scrolls V: Skyrim is a first person action RPG with a huge open world. You play as a dragonborn and must fight to stop the dragons from destroying the world.
Pro Huge variety of mods
Bethesda Softworks has upheld a tradition of releasing their internal content-creation tools to the public since Morrowind (2002). Many modders transition to new Bethesda games as they are released, bringing their experience with them and helping newcomers through forums and wikis. As a result, Skyrim's mod selection is outstanding in both variety and quality.
Pro Deep lore rivaling classic fantasy literature
Skyrim inherits the stories and world-building of The Elder Scrolls series, which stretches back 20 years. It has numerous stories surrounding the various races (orcs, elves, lizardmen, demons, etc.), mythical beasts, gods, cataclysmic events, parallel worlds, and just about any fantasy trope you could think off. What's even better you can read the lore in books found in-game, allowing you to immerse yourself for countless hours.
Pro Unrestrictive skill-based RPG system
Skyrim has no set character classes or equipment/spell limitations. Instead, it allows you to form your own class based on how you decide to play.
For example, sneaking increases your sneaking skill, hitting an enemy with a shortsword increases your one-handed skill, taking damage while wearing leather armor increases your light armor skill, and so forth. You can you play however you want and the resulting character will be a perfect match for your playstyle, giving Skyrim a different feel from other RPGs.
Pro Total freedom in how you choose to play through the world's different factions
You can set off to any of Skyrim's different towns and discover new storylines from interesting factions that flesh out the world and the lore, with great characters and their own absorbing narratives to get lost in. There are a good number of these factions, like the scholars at the snowy College of Winterhold, the secretive assassins of the Dark Brotherhood, or the cohort of rogues and bandits of the Thieves Guild. After picking whichever faction you want to learn more about, you can eventually become a Master of the guild and learn new skills for your character. Playing through each of their individual stories lets you really feel like a member of the faction you choose, like with how the Thieves Guild sends you on missions to pick locks and steal valuables without getting caught by the guards.
And if you only get through some of the faction's story and decide you don't enjoy it, you can easily go find another one and play through that one instead. There are no limits on how you play through the plot, with Skyrim giving you the flexibility to pick up stories, set them down, and come back to them whenever you feel like it.
Pro Massive sandbox to explore at your own pace
The in-game map is absolutely gigantic. There are so many places to go and so much to do in the world, easily giving you hundreds of hours of content.
Exploring the wide range of environments, from the snowy mountains to the richly-detailed towns and cities is such a joy because of how lush and beautiful everything is. Wandering around often surprises you with new side quests to find off the beaten path, with new characters to meet and history to learn about in whichever area you find yourself in. You can get into all sorts of battles with powerful enemies or stumble into hidden dungeons with awesome loot at the end. Or you can sneak around towns at night stealing peoples' stuff while they're asleep to sell everything off for money. And there's just a ton of other intriguing secrets and fun diversions to discover as you adventure throughout the world.