For Home Console:
Wii Sports - this game was both insanely popular and revolutionary - it was what brought motion gaming to the world, and had a very large presence in mainstream media.
Just Dance trilogy - it was more or less the first REAL party game. Party games before were Smash Brothers or Starcraft and pizza; Just Dance is an actual true party game, and it has become insanely popular.
Wii Fit - if only because so many people will have balance boards sitting around their house years and years later.
I would like to say Mario Galaxy and Assassins Creed 2 trilogy, but my gut says no. While Mario Galaxy may be potentially the best game available, it is not something that broke ground with many people like the three games I mentioned above did. Classics are most often not determined by what people consider high quality, they are determined by memorable appeal to people: even games that have small fan bases like Earthbound have become classics.
Indeed this generation was a little strange - I think it is that the VAST majority of games were just improvements on things from last generation - and they will be improved on next generation. Sony and Microsoft got into motion controls too, but in the end, no classics will come from that since they're just really just imitation Nintendo. Many RPGs (even Dragon Quest) were made very open ended, and not closed stories and really interesting characters like in Chrono Trigger or Xenogears, and these open sort of games don't become classics - they get updated and improved upon.
DS is a whole different story.... I would say there's a motherload there, but I don't want to think about it right now. To throw out one series that I think will definitely be a cult classic: Phoenix Wright: Ace Attorney.
I describe myself as a little dose of toxic masculinity.
