I don't think I'm going too far out on a limb by saying that Omegas seem to be the most common (and quite possibly most sought after) vintage watches on the market. That's not too much of a surprise - just my opinion, but with Omega's level of craftsmanship, there will probably be more than a few well-serviced vintage seamasters ticking away when the apocalypse finally comes.
That said, I'd looking for takes on the most underrated vintage watches out there. To clarify, I'm looking more for brands than particular models: brands with beautiful pieces, solid reputations for quality, but nonetheless fly under the radar in the vintage watch world.
Just to start things off, my vote is for Rado. There are lots of dedicated fans of vintage Rados (including myself), but I feel that vintage Rados don't get the attention they deserve. Perhaps I'm biased, but my vintage Rado Voyager is a favorite from my collection. Bought it for a song a few months back, and couldn't be happier. Although it's a 35-40 year old watch with no recent service history, it's still one of the most accurate watches I own. (Knock on wood - I'd hate to think that a service issue popped up the moment I boasted about its accuracy.)
What do you think? What are your votes for underrated vintage watches?