They were called the next ABBA, and for a brief time that looked like it would be the case. With two men, two women from Sweden, and a bubblegum Dance sound, Ace of Base captured the attention of fans in numerous countries. As popular as their pop melodies were, their peak did not last more than two albums (not very ABBA like) and as such will struggle to receive serious Hall consideration, which ABBA was able to achieve. 

The East Coast response to the Seattle scene brought the world Helmet, an Alternative Metal band that blended Metal with other influences to create their own unique sound. With powerful drumming and disjointed rhythms they carved their own niche in the Alternative music scene and successfully paved the way for other East Coast Metal bands to follow. They may not be a Hall of Fame band, but they established more than just a cult following.

Although they were not commercially successful, Uncle Tupelo has often been cited as one of the more influential acts in Alternative Country history. With strong elements of traditional Country music and the Punk ideology that the band grew up with, they became underground stars. Uncle Tupelo will likely not get indicted, although its lead member, Jeff Tweedy has an excellent shot with his later effort, Wilco.

One of the harder sounding of the Hair Metal genre, Mark Slaughter and his eponymously named band, Slaughter, delivered two successful albums in 1990 and 1992 respectively. However, like so many of their ilk, they were dismissed shortly thereafter as jean jackets gave way to flannel. With all that said, should there ever be a Hair Metal Hall of Fame, Slaughter would be a decent candidate for it.