You know, I'm no big fan of a LOT of comics of the 1990s, but painting with this broad of a brush seems to missing a LOT of good comics.
Here's a sample of comics from the 1990s:
Kurt Busiek's Astro City America's Best Comics (including Tom Strong, The League of Extraordinary Gentlemen Mark Waid's initial run on The Flash Kingdom Come Marvels Warren Ellis' run on Excalibur Transmetropolitan Planetary The Authority Preacher Bone Sin City Death: the High Cost of Living The Invisibles MOST of Gaiman's Sandman 100 Bullets Hellboy Sandman Mystery Theater Death of Superman/Funeral for a Friend/Reign of the Supermen Peter David's runs on Hulk, Supergirl, Young Justice Thunderbolts The ENTIRE Milestone comics line
I mean, seriously dude...there were good comics from every publisher and in every line. Just because image put out some crap and the X-titles went south for a while along with some other big names doesn't mean that the entire decade was a lost cause.