re: Should every man own a suit?

Yes. Even if you do not need a suit for your work, and even if you hate wearing a suit to social functions, you should have a suit for certain occasions, i.e., a wedding or a funeral or a graduation. If anything, it shows respect for the occasion.

If you seldom wear a suit, I still do not believe that you should cheap out. With moderate wear, a good suit can last you ten, twenty, thirty years - or more - as long as it is conservative in terms of the details.

As for what you should own, there are a multitude of options. If you only intend to purchase one suit (and I think two should be the minimum), it should be navy or grey (and preferably dark grey - just shy of charcoal), and it should preferably be fully canvassed (or at minimum, half-canvassed). Why? Well, in a fused or half-canvassed suit the shape of the garment is accomplished by gluing the wool to "fusible." After a certain number of dry cleanings (or, more specifically, if the dry cleaner applies too much heat), the fusible will become unglued and separate from the wool. This causes bubbling. Conversely, in a fully canvassed garment the wool is stitched to horsehair canvassing which provides the shape. The increase in longevity is absurd with a fully-canvassed suit.