Having volunteered at a big-city bike co-op for a number of years, I've interacted with clients who come to us scavenging for vintage parts, or just to show off their latest find. I've seen many many classic steel frames from the outside and the inside.
The highest quality workmanship I've ever seen on a bike: a 80's Pinarello Montello. My favorite vintage bike: Vitus 979. My favorite semi-vintage steel bike: any Lemond with a 853 frame. If I were to buy a new steel frame: it would be a Ritchey.