Carcassonne?
I also quite like Caverna. Its Agricola rebuilt as Dwarf Fortress.
Also 7 wonders. Its a great game. You get a hand of 7 cards play one and pass the others. You do that through 3 ages alternating directions of passing. It can play 3-7 players and is great with any number. There are 7 different types of cards, which means several different paths to victory. Best of all since everyone plays at the same time its a nice quick game with any number of players.
The theam is the ancient world for those that are intetested in theme. Its a great game and very well designed. Anyone that wants to design games should try it, just to see what they have done.