Japan has brought us nearly as much awesome garage rock over the years as Sweden, and that's saying something. Teengenerate is second only to Guitar Wolf when it comes to notoriety and all-out brashness for Japanese garage rockers. If forced to pick between the two, I would actually take Teengenerate because they're further from the line dividing music from utter chaos than Guitar Wolf is (Seriously, Guitar Wolf can be absolutely brutal whereas you don't need a particular mood to be able to listen to Teengenerate).
Anyway, Smash Hits is exactly what it sounds like: a greatest hits compilation. I don't know if there are any glaring omissions on this compilation. I only know that it's some nice hard-hitting undecipherable garage rock and that suits me just fine.