Smart-watches are useful tools — that's the whole point — but it's hard to imagine anyone handing down his Apple Watch to his son, much less his son handing it down to his child. For that, you need a classic timepiece. These 40 models are to watches what the 911 is to sports cars. This is less an impulse buy than an investment: The least expensive timepiece on our list, the Swatch Watch, will set you back $60; the priciest goes for $78,500. But that watch "will look as good on your wrist today as it will in 10, 20, or 30 years," says Leonardo Solis, a Boston-based watch collector. And your son will appreciate it even more when it's his turn to wear it.