For me it was honestly the late 80s to the 90s up to maybe 2001 or so. Sure there were "gimmick" covers and "Bad girls" and such, but at the same time I think it was a slightly more accessible time. Other than the once or twice yearly multi-title crossovers - like the X-Men comics and Spider-Man comics did at least a couple of times a year you could pick up any comic, get a story and feel like you had something in your hands. The 70s were like that too, but I liked the later 80s, to the whole of the 90s and at least the first few years of the 2000s - until they got to Avengers Disassembled and House of M. That whole thing just screwed up the Marvel Universe something fierce. Characters were no longer as "heroic"
People bash the 90s with the "grim and gritty" and "big guns" and all that, but honestly most of that was still relegated to a handful of titles. The "Midnight Sons" imprint that included Ghost Rider, Spirits of Vengeance, Morbius, Dr. Strange, Nightstalkers and Blade, were the "Grim, gritty, spooky" end of Marvel. And it was cool because it was like you were treading 'where angels feared to trod' compared to the slightly lighter and more action oriented stuff from the rest of Marvel. DC was pretty good around that era too - okay so Knightfall was kinda sucktacular with John Paul Valley, but then again it was the first time that Bruce Wayne wasn't the Batman for a while. That was actually kinda mind blowing. I remember calling my best friend, Tom, up after I got my copy of the issue where Bane breaks Batman's back and reading him the whole exchange and we were both just shocked that it happened. Or when Superman died. Whoa that was one helluva story. I mean... Superman WAS DEAD! There was media coverage, there was like almost a year of stories until the one true Superman finally returned. Then... it kinda petered out a bit after Zero Hour and the whole Kenny Braverman out of nowhere/Death of Clark Kent crap... I kinda tuned out a bit after that. Then I got back into it around the time of the Wedding of Lois and Clark. But really the early part of the 21st Century was pretty good. It wasn't until all the crisis stories and deconstructionist bullshit that's gone on the past 7 or so years that has really kinda.. made things iffy.
Course I still buy new stuff, I have to admit I did enjoy parts of Civil War... was kinda cool seeing hero vs hero in a slightly realistic way, not just the usual "They must be mind controlled... fight them!" stuff that used to happen.
But y'know the cool thing is... back issues cost next to nothing so if you don't like the current stuff, dig into the back issue bins! I mean my LCS has a whole long box full of old decovered 60s comics that he sells for a quarter! I mean c'mon you can't beat it! And most every comic shop has at least one or two long boxes full of maybe one or two year old comics for a buck or less, so even if you missed out on last year's stuff, you can fill in the gaps for a whole lot less. I rarely if ever pay cover anymore.