Rocko wasn't one of the original Nick Toons. I'm almost sure there were only the three: Ren and Stimpy, Rugrats, and Doug. (Each classic in its own way!) At first they were produced by MTV and distributed through Nickelodeon, as I recall.
If you're talking about the original Snick lineup, there were Clarissa Explains it All, Roundhouse, Ren and Stimpy, and Are You Afraid of the Dark. I hated Ren and Stimpy; I could never get into it. But it's hard to deny how much of a classic it was. Just not my taste. Who can forget LOG ?!
It's better than bad -- it's good!