Settlers is awesome, but Carcassone is fun, too.
One point Chad didn't mention is that the Eurogames are also good for multilingual groups, because they boards (or hexes, or whatever) are usually writing-free. The designers hope to sell across borders, so you can buy the game, and rules in your language aren't in the box, you can probably find a translation with your favorite search engine or by contacting the company.
