Outkast disbanded after Idlewild but Andre 3000 and Big Boi still make solo projects. Andre is coming up with an album soon but it's not a rap/hip-hop album.
His first 3 albums are great. The Eminem show is probably Em at his best from a technical perspective. 2002-2004 is when he reached his peak in terms of flow, delivery, and lyricsism. Encore was overall bad but had some great songs such as Yellow Brick Road, Mockingbird, Love You More, or We as Americans. Relapse I initially didn't like but the imagery and creativity grew on me after a while. Not a big fan of Recovery but people liked it. MMLP2 was alright. Everything after that is trash-tier.