DarrkPhoenix: My short response would be: I'd consider Gothic 1&2 absolutely exceptional games in the open-world RPG genre, and you really can't go wrong with them.
Now, for the longer response.
With regards to character creation, the starting character in Gothic games is set, but can then be developed in many different ways, depending on the faction you choose to join and the skills you choose to develop (and there's nowhere enough learning points to become "master of everything", so you definitely need to make careful choices on character development).
With regards to open world vs linear story, the main storyline is indeed linear (same as how the main story is linear in Elder Scrolls games), but the world is still pretty much completely open. The Gothic games also tend to make use of "soft" barriers to keep you from wandering too far and too randomly (unless you're really intent on doing so). For example, in Gothic 1 you'll be warned to stay away from the orc controlled area; you can still run around that area without anything stopping you, but unless you're very careful to avoid the numerous orcs patrolling the area you'll find out quickly and painfully just why you were warned to stay out of there (at least until you're a big enough badass to handle orcs).
As for other things to recommend the game, think back to when you first played Morrowind- the sense of being just thrown into this huge and unknown world, and the excitement of slowly exploring it and learning how to get by in it. In my opinion Gothic 1&2 manage to pull off that feeling even better, and also include a real feeling of development as your character progresses and is slowly able to handle more and more of the dangers of the world. The world is also designed extremely well with very good use of space, making exploring every little bit of it well worth it. I'd also consider the combat in Gothic 1&2 very well designed (although it requires a bit of getting used to), with the need to observe opponents, read their attacks, and develop good counter-tactics making combat interesting an often exhilarating from the beginning of the game all the way to the end.
Finally, for a bit of background on my own tastes, I spent probably over a thousand hours on Morrowind, several hundred on the NWN games, and thought Two Worlds was a boring, repetitive grindfest. And I think Gothic 1&2 are absolutely excellent and highly enjoyable games (Gothic 3 was fairly mediocre, although Piranha Bytes got their mojo back with Risen, which is also excellent).

sera: I enjoyed 3 but it would have been far better if it didn't carry the name Gothic, it just can't compare to the first two.