I originally ordered Carcassonne on a whim after hearing great things about it. I really had no idea what to expect, or even if I was going to be able to figure out how to play.
I was extremely surprised at how much fun this game was, and how easy it was to learn and teach others how to play. I am not traditionally a board game player, but I fell in love with this game.
It usually is a decently short game and even with two players it can be finished in about 20-45 minutes depending on how long you think about your moves.
The real thing that affirmed this games addictiveness in my mind, was when my sister (who hates board games, and told me she would never play Carcassonne with me) after playing the first time, kept bugging me to play. She fell in love with it as well.
I think that this is a good game to consider for families, or just between friends. It's decently easy to learn (learning about farmers can be a little tricky at first) and is always a good time.