When I think of "90s animation," the first show that jumps to mind is Ren and Stimpy. Please tell me you've seen that. The nickelodeon episodes, not the spike TV ones.
Also the 90s X-Men animated series, but I assume you have seen that. If you haven't, you can probably safely skip it... it was overwrought emo teen angst wrapped in spandex and animated at about 5 fps.[DOUBLEPOST=1451581906,1451581641][/DOUBLEPOST]And now that I'm thinking about it, of course, the floodgates open. Johnny Bravo, Cow and Chicken, Batman TAS, Animaniacs/Pinky and the Brain, Courage the Cowardly Dog, Beavis and Butthead/Daria, Dexter's Lab, Rocko's Modern Life, Ed Edd and Eddy... 2 Stupid Dogs was surprisingly layered and got all kinds of crap past the radar which made college-freshman GasBandit laugh his ass off.