I'd say it really depends on what would you expect from the game. As far as exploration goes, there are some areas which don't have too many things to explore, but at the same time there are those, which are filled to the brim with stuff to see (even if some of those are small, scenic places). Dungeons vary in size from small (a room or two + some corridors) to massive complexes (with a cave the size of a small state).

If you want your actions to have a visible impact on the world, it's not really that good - while some things do change, the ingame impact of these is rather small (though as far as the world is concerned, they are important).

The plot isn't the strongest part of the game (especcially if you didn't have any contact with the series - while anyone can enjoy it, hardcore fans who get to meet certain people in the main quest can get an awesomegasm ;) ).

While it does have many flaws, for me it is a really fun and enjoyable game - and if you'd get it on the PC, the world of mods openes - and those can be almost whole new games.