I personally do, but I can also see where someone is coming from if they don’t. I actually asked this same question to several of my close friends a few months ago when I had a “classic” gaming night at my place; I was a little conflicted as to whether I should have included 5th generation systems in it or not. Several people gave good reasons why they aren’t (the advent of disc media and 3D graphics being the primary ones cited), but ultimately I ended up seeing them as classic for a few reasons. We’re now in 7th generation, two generations removed from 5th. People fondly reminiscence about these systems (especially the PS1/N64) just like how people do for the earlier generations. The games and systems also seem primitive (tech-wise anyway; I still think 5th generation had a ton of games that outshine anything recently released) to most consumers, who probably couldn’t sit down and play many of these games based solely on the dated graphics.
I also think it is easier to designate the earlier systems of 5th generation as “classic” (3DO, Jaguar, and Saturn) whereas it is somewhat problematic for people to do that with the PS1 and N64. I don’t know why but I wonder if that’s because both Nintendo and Sony are still in the hardware business and/or because of the popularity these systems enjoyed during their heyday? For some reason it’s easier to label a game like Gex “classic” whereas its hard to do that for something like Resident Evil, even though both came out of the 5th generation.
But I can also see the other side of the coin, so I really think it boils down to a matter of preference at this point.
Just my two cents. :-)