Krist Novoselic – yeah, he generally gets his due from hardcore bass fans but most people when they think of Nirvana, they think of Cobain, or how Grohl went on to form Foo Fighters. Novoselic tends to get overlooked, as do his contributions to Nirvana's sound. He might not be the most technically proficient bassist around, but he has kick-ass ear for hooks, grooves and melody.
Muzz Skilling – original bassist for Living Colour. A fantastic bass player, I could practice ten hours a day for a hundred years and never be as good as this guy. His work on the LC album Vivid still blows me away.
Melvin Gibbs – if James Brown was the hardest working man in show business, Gibbs has to be the hardest working bassist. He's done so much, has played for so wide a range of bands, that chances are you've probably heard him and didn't even know it. An amazing bass player, mostly known for his stint with Rollins Band during the ‘90s.
Doug Wimbish – another guy who, like Melvin Gibbs, has done so much over the years but never seems to get his due recognition. Also like Gibbs, he’s probably one of the best bassists on the planet.
There are more but I don't want to hog the thread.