"They are so different." How? In what ways? Specifically, in the sense of measuring how "noir" they are? Go back quickly and quantify how much of the "noir-o-meter" was discarded and replaced in order to create the "neo-noir-o-meter"...
"They do different things." What is that for each? How and why are they different? What is the point of intersection and disjuncture? Character? Visual? Plot/narrative? Social/societal assumptions?
"They explore different worlds in different ways." Try to characterize the difference in the worlds. Modern vs. post-modern? Where does that change take place? If we looked at the approaches to making these films in the 80s 90s, 00s and 10s would we find observable differences in how these worlds are characterized and explored? And how does it affect the filmmaking and the audience response? In terms of noir/neo-noir, is it subtext vs. in-your-face? Is neo-noir used more or less ideologically in terms of exploring social mores and individuality within those worlds?
Will there be as much of a range in neo-noir that films which have only the barest reference to actual crime can still be credibly included in the context of "noir," or have the genres that seem to have coalesced in the aftermath of the noir cycle pushed them into their own categories?
Returning to the idea of the list, one might use the IMDB to collect a list of crime-thrillers (I don't think they have a "neo-noir" category...) from 1967 to now that have a 7 or higher user ranking. That would add one data element to the lists previously compiled that might help focus on which films would eventually be part of a smaller list (say, 250 films) that would be the likeliest to wind up on a "top 25" for neo-noir.