I would consider the early 90's Cannondale R series as vintage classic. Made of aluminum and what is now a classic design. My friend owned a '93 Cannondale R400 and gifted it to me when his eyesight failed to the point he could no longer ride. I was amazed a bike could be made of aluminum and be durable. That R400 was always a joy to ride and I owned it for 20 years before I ended up selling it after I could no longer ride it due to lower back issues. A classic design that has stood the test of time while also being mechanically simple.