A lot of people are posting their Best of 2010 reading lists, but since I didn't read much this year I'll post my favorite games of the year instead. These didn't come out in 2010 and I didn't necessarily play them for the first time in 2010 either, but they stick in my mind.
If you're a huge fan of Monopoly and other "roll the dice and move" games, you might not like these. Then again, I grew up playing Monopoly and now love the new German board games from the likes of Rio Grande. These games often include the mechanic whereby everyone in turn chooses what to do and then everyone does it, rather than everyone doing something different based on their dice roll. Many also include an element of cooperation as well as competition. We taught my 12- and 15-year-old nieces to play the first three games on the list this week, and they picked them up quickly and enjoyed them a lot.
Carcassonne - Use hex pieces to build roads, fields and cities; cooperate or conquer for points.
Kingsburg - Influence the king's advisors to obtain resources, build buildings and hire soldiers that help you defend the realm against annual monster attacks.
Bohnanza - A deceptively simple card game in which you plant bean fields and harvest them at just the right moment for maximum profit.
Settlers of Catan - Another very simple but addictive resource-based game (there is a sci-fi version of this that I haven't played but I've read that each player gets a 6" tall mothership - yowza!).
Puerto Rico - Produce crops on your island plantation using slaves... ahem, colonists, and ship the goods back to the old world.
Age of Empires - Choose actions, collect resources and colonize countries in the new world; convert or conquer to expand your colonies.
And some sci-fi ones...
Race for the Galaxy - Explore and settle new worlds, produce and sell goods (a neat little card game that MCP always wins).
Ad Astra - Explore and mine planets for resources to build spaceships and colonies.
Galaxy Trucker - Silly but fun game where you build a spaceship out of jigsaw pieces, then face various dangers to see how it holds up.