I think I would like a 69-71 Chevelle SS
I have always said a 1970 1/2 Chevelle in Hugger Orange, with the dual white racing stripes down the middle. Gotta be a manual, and honestly the engine doesn't matter to me. Just give me one that has had a full restoration to brand new specs using the correct parts.
2nd place (if the lottery friend is feeling REALLY generous): same conditions above in terms of restoration, a 1963 split rear window Corvette.