This is the highest rated 90s Nicktoon on imdb
After a quick search around of the various nicktoons it's pretty cool to learn that this show, despite its lack of love at the time, now has such a healthy following that it outranks all Nicktoons I came across.. and by a considerable margin. The highest I found was a 7.6 for ren and stimpy and rugrats.
PS. SpongeBob has the same rating as Rocko but I don't count that as a 90s nicktoon