Monster Hunter Tri is the best game evar. Well, one of the best Wii games anyways, other than that I'd recommend the following:
Wii:
Tales of Symphonia, gamecube action RPG, 4 player simultaneous co op, great combat, great dialog, and reaaaaaallllllyyyy long. Only notable downside is the stupid cutscenes with the really poorly rendered faces... search for it on youtube and you'll know what I mean.
PC:
Team Fortress 2 is fucking 'mazing, and now it's free, so go download it on Origin.
HAH, NO.
Other than that, anything by Valve is great, Minecraft is good fun, Diablo 2 is cheap and great (I found a complete set with all bonus content and modding tools at best buy for $15
), Mari0 is fun, Sanctum is great and really underrated, and Star Wars: Knights of the Old Republic is better than Skyrim, and made in 2000. Seriously, check dat shet out, it's only like $4.32 on Steam