I bought Monster Hunter 3 Ultimate (MH3U [see what I/they did there]), my console refuses to read the disc and claims it's dirty (despite being brand new and clean as a whistle); I got the game exchanged and the problem persists. But everything else works just fine (I have an old copy of Brawl that's been Skip Dr.'ed to Hades and it works just fine). So I can't say that it's either the disc's fault because it only happens to MH3U, or the console as there is nothing wrong with the game as far as I can tell. And I really don't want to have wasted $60!
TL;DR Got new clean game, says it's dirty & won't read, will only not read said game.