I bought a few over the years but never built them (lost interest in building nascar kits). I have tried selling the few I have along with thinning my collection and I can't give them away. About all they're good for is kit bashing for parts.
So many great years it's hard to pick just one. I would go with a minimum of three 67,68,69. Those years seem to have left over styling cues from the early 60's and some of the coming changes of the early 70's.
I invested in an Optivisor years ago, I have gone to the next power lense since then. Lol. But that's Ok, I refuse to give in to being older. I've got too many 1/24-25 kits to build as well as a few 1/43. Spend the extra to buy the Optivisor they have glass lenses which don't scratch like the cheaper versions which have cheaper plastic lenses.