acid bath is one of the best sludge metal bands to ever do it in my opinion, so i recommend them first. other bands i like include eyehategod, soylent green, human waste project, shrüm, goatwhore, dirty rotten imbiciles and my ruin. crowbar has some good stuff, so does die so fluid and mushroomhead. i also listen to oldschool stuff like death, at the gates, slayer and deftones. all these bands are a wide variety of styles and subgenres of metal so you should have fun with these :)