Its all realtive......
Rate them? On what?
What the older crowd is fond of?
What the younger crowd is fond of?
Build quality?
Race history?
Who trained who?
From a historical perspective?
In general it seems as if De Rosa and Colnago both work their way to the top of the list. Both are considerably different 'builder's', believe what internet lore you'd like. At the end of the day certain makes brong more $$$ than others and that in itself is a big part of the rating system.
I look at a combination of history and build quality but that in itself begs one to ask, "what is build quality?" Is it thin, long point lugs? Pantographing? Consistency from frame to frame? In all honesty I've never been overly impressed with Italian 'build quality' which shouldnt be confused with craftsmanship. In general the quality of Italian chrome work is about the worst you'll find, they tend to have delicate paint and some haveatrocious decals.......but those flaws dont mean tcraftsmanship isnt there.
I dont buy into the, 'but X held the torch and brazed it together'. Big deal. How many torches did Masi hold in California? None. I'd prefer to have a skilled craftsman holding the torch who's building to a skilled craftsman's design. The best brazer in the world cant build a great bike if he's build to bad design or concept and a great designer cant build a great bike if the brazer sucks.
I've onwed a variety of bikes over the years, only a few have been mentioned here, I've worked on some I haven't owned. My opinions are simply that opinions.....other disagree, I want them to. But I want to understand why they disagree with me, its how I learn.
From a build quality perspective the best frame I've ever owned is a my Dave Moulton Fuso follwed by my Waterford Paramount. Both have superbe build quality detail, the Moulton has a double mitered seat tube/ down tube junction which is something my De Rosa doesnt have. Strip the paint off a Waterford Paramount and no one could tell you it wasn't Italian.
At the end of the day Italians are Italians and they're what people tend to collect.....based on whatt I've owned and worked on:
Colnago (It just rides so nice.....sooooo nice)
De Rosa
Palletti
Basso (nice bike but not in the Palleti, De Rosa, Colnago)
Giordana (Gita imported, Italian build)
Guerciotti (owned both pre and post TSD bikes. Superbe chroming on the TSD bike)
Tommasini (major flaw in the brazing/chrome work. Never should have left Italy the way it did. Also the most highly crafted bike bike based on decals or lack thereof)
Bottechia (Built from frameset fro customer. Thought the chrome work was mediocre and the paint work edging sloppy. Delicate paint)
Rossin (Didnt like a single thing about it)
Again...simply my opinions, it doesnt mean I'm right or wrong and it doesnt your right or wrong.