I would included Angry Birds, even though I've never played it, due to the role it played in moving mobile and downloadable games forward. Such games are now a large and growing percentage of the gaming market that didn't exist before the current generation. Some of the most creative and unique games currently being developed are from indie developers that are making smaller downloadable games.
There are certainly other downloadable titles worth mentioning, but Angry Birds is the first really big hit I can recall off the top of my head.
While we're certainly a small percentage of the gaming community, it's worth taking a look over the games we're mentioning and how few if any of them are Wii titles.