Played my first game of Carcassonne last night. This is a German-made "designer game" (I dislike that term, but it has persisted) with an even more abstracted basis than Settlers of Catan. The core mechanics are beautifully concieved, and the game supports a wide variety of ludic play styles; the game supports agonistic play, with a fair component of alea, but there is also simple mimicry in the building of the landscape. A real strength of this sort of abstract game is when it is designed for agonistic play but supports co-operation in its internal economy as a natural consequence of the simplicity of its mechanics.
It has several of the traits required to make a successful boardgame - it can be played in less than an hour, it supports a good number of players with no change in the play time (2-5 players, but works just as well heads up as in a larger group), you can learn to play in minutes, the turn sequence is trivial, and the aleatory element is sufficient to allow anyone a chance of winning, but not so large as to undermine player skill as a key factor. Plus, the pieces are satisfying to play with - the wooden "meeple" counters, like the settlements and cities in Klaus Teuber's masterwork, are deliciously tactile. The absence of a setup phase (an unavoidable overhead in Settlers) also smooths the play experience.
At a comfortable price point, I would suggest that anyone who enjoys hobby games, and especially those looking for boardgames which can be played by non-hobby gamers, will not regret picking up a copy of Carcassonne.