You should. Gothic is good, for the reasons mentioned. It also was my first contact with what later became one of my favorite bands, who have a guest appearance in the game.
Gothic 2 is a straight-forward improvement of the first part with lots of recurring characters. And all of the good parts of Gothic are still there. Though balancing was a bit off, as the beginning of the game was hard, but became too easy once you advanced into the higher tier of your faction, especially if you were a mage who saved lots of skill points: A brutal first act as novice, but once you became master you could depopulate entire landscapes with rains of fire, hordes of skeletons and summoned demons while hardly raising a finger (though not both of the latter at the same time, as they did not get along long well). There was an addon, Night of the Raven, which added some extra areas and side factions, but skewerd the balance a bit too much in the opposite direction, as skills were now so expensive you had a tough time training your character properly.
Gothic 3 was a technical disaster at launch, but I heared that with all the updates, patches and community fixes, it became a quite good game eventually. However due to its issues it failed so hard that the studio lost the rights to the brand, and Gothic 4 Arcania was made by someone else and has hardly anything in common with the other three games.
