In a nutshell: Epic, fun, darkly humorous, and there is a lot of dragons.
This is the kind of game that brings me back to my KotOR days. The combat is old school RPG and the story is interesting. The "origins" stories change depending on your Race and Background, so you can get more than a few playthorughs on the beefy campaign. The side missions are usually small tasks, but still make you feel invested in the game world. Thar said, it is not like Fallout or Elder scrolls. It is not as open world, and focuses more on the story than questing. The combat is significantly slower as well. If you dislike slow tactical combat, like the original fallout games, then stick to Elder Scrolls or Fallout.
A bit of warning though, the gameplay is challenging at first so you may need to turn down the difficulty at the start of the game. Like most RPGs, it gets easier as you level up.
The best part of the Ultimate Edition is the add-on content, which adds at least 10 hours to the game. If you want the game, this is the definative edition. The extra add-ons are fun and immerse you further in the story. The only problem with the add-ons is that you must have internet to use them (which is inconvienient with my skeatchy connection. Other than that, the addon does suffer from a story shattering issue. With the ability to import your warden from dragon age. (spoilers) if your warden died, you can import him even if he is dead, which ruins the story. If you do so, you will be rewarded with the items you had in the main story.
Quite simply, this game is a must buy for any RPG lover or any PC gamer with self respect, because this game is awesome.
Note: I dont normally say this, but I must issue a parental advisory for this one. The good news is that the only worrysome category is the violence. There is head lopping and blood. A lot of blood. There are pools of blood, blood flying out of you, and blood on your character for the majority of the game due to the frequent combat scenarios. Scratch that only worrysome part. After playing more of the game, the sexual content is infrequent and mild, but still present.