First, Electric Six! They had a few novelty meme type hits that aren't their better songs just out of comedic value, with their best stuff remaining on the obscure side. Huge cult following though. Bizarre blend of countless genres all with total nonsense lyrics.
Second, KMFDM. Industrial band I loved as a kid. Definitely a band that many people may have heard of, and heavily influential in certain circles, but never had mainstream success almost by choice (had a feud with MTv back when it was that or nothing). Personal favorite song is Anarchy, but won't link it here because of language/objectionable content. Instead, linked song is Ultra, probably their best known song in the 90's except maybe Juke Joint Jezebel(which was on Mortal Kombat movie soundtrack, which despite being the soundtrack to a video game movie was crazy successful and chart topping since it was a crazy good compilation of Industrial, hard rock, etc. songs from major 90s bands in the genres like Stabbing Westward, Type-O Negative, and Gravity Kills).
