How much time and money ya got?
I guess the classic old models would include factory engraved Single Sixes, 10" barrel flattops, 7.5" .44 flattops, factory chrome or nickel Super Single Sixes, factory brass frame Blackhawks and Super Blackhawks, boxed Lightweight Single Sixes, verifiable black trigger guard Bearcats (not Super Bearcats), Bearcats in the 1xxx serial number range, any of the 1-2 digit serial number guns, 4-5/8" barrel Super Single Sixes, long grip frame Super Blackhawks, 6.5" barrel Super Blackhawks, white boxed Super Blackhawks, non-prefixed serial number .357x9mm convertible Blackhawks especially in the 4-5/8" barrel, XR3 frame guns with factory stag and especially ivory grips, high polish .357 flattops, case hardened .357 flattops, factory second "S" stamped guns, duplicate serial number "D" stamped guns, mis-marked guns, guns with non-cataloged but verifiable barrel lengths or other features, non-INC barrel .41 Blackhawks, XR3-RED flattops & other late-shipped guns with mixed chronological features, and on and on.
Then with New Models, the list is probably longer but the values are not as high (yet).