I wish I had been born either during the period of 1946 - 1951 or in about 1980.
1946 - 1951 because it would have meant coming of age in the mid to late 60's. That seemed like an awesome time to be a young person (as long as I didn't have to go to Vietnam, that is).
I say 1980 because this way I wouldn't feel so old on these message boards