I had a subscription to Dragon Magazine back in the 1980s. I remember when the issues would show up in the mail. They tended to come around the same time every month (maybe the 5th or so? that seems familiar), and I’d be waiting for them. They were just about the best thing to show up in the mail.
My favorite regular article series were, probably, the Marvel-Phile and the “Ecology of…” series that was written by, I think, Ed Greenwood.
Each article in the “Ecology of…” series focused upon a particular monster. I fondly remember articles on hook horrors, aboleths, and rust monsters. Generally, they were once written ‘in-character’ from the point of view of a sage who was giving a scholarly lecture or producing a treatise. The articles added depth and some internal consistency to monsters that might otherwise be difficult to use in a campaign that values some level of verisimilitude or internal consistency. There were usually very few game mechanics in these articles. Most of them focused on the good sort of fluff – handy information that could be used to generate plot hooks, interesting encounters, and fleshed-out backgrounds.
I haven’t read a Dragon Magazine since 3rd edition came out. Apparently, they still do “Ecology of” type articles. I don’t know what they are like anymore…. and, despite the fact that most of the monsters actually listed in the description don’t sound terribly interesting, I want this. Badly.