Games that I own with a white case:
- Valis 2
- Final Zone 2
- Implode
- Meteor Blaster
I have one of my Y's 1 & 2's packed away, along with my Gate of Thunder's original case (printed a CD tray liner for GoT, and have CD in that case). Though, from what I recall, GoT 3in1 was also a white case.
There are other odd things with some Turbo games. Such as Champions Forever Boxing. There are 2 different Hu-Cards for that one, one is mostly black, the other mostly red... I think....
There are also 2 different Y's 1&2 CD's. One reads Turbo Grafx CD on the CD, the other reads Turbo Duo.
That's about all the peculiarities that I know of off hand.