In my opinion, the best guns are from the 1974 genre, the ones with the fleur-de-lis impressed checkering like shown above in 357wheelgunner's post, the polished blued steel, and with the chrome plated carrier. Some time later they dropped the chromed carrier, and up until the changed to the fancier checkering pattern (1979?) I think the guns were almost as good. Of course, individual guns will vary.
I had a friend who got an 870 about 1983, and it had some kind of small problem. he sent it to Remington to fix it, and when he got that gun back it was undoubtedly the smoothest pump gun I have ever gotten near. And, there was absolutely no evidence anywhere as to what they had done because every little part had apparently been reblued as necessary. When I found out he sold it I was darned sorry I didn't get a crack at it.