Butch Vig is incredible. He has to have made a goddamn mint as a producer. In the 90s he produced:
1991: The Smashing Pumpkins - Gish
1991: Nirvana - Nevermind
1992: Sonic Youth - Dirty
1992: L7 - Bricks Are Heavy
1993: The Smashing Pumpkins - Siamese Dream
1994: Sonic Youth - Experimental Jet Set, Trash and No Star
1994: Helmet - Betty
1995: Soul Asylum - Let Your Dim Light Shine
and then obviously all of his Garbage stuff
About the only producer/engineer that I might admire more from their 90s catalogue is Brendan O'Brien, who was responsible for:
1991: Blood Sugar Sex Magik - Red Hot Chili Peppers (Engineer, Mixer, Organ, Mellotron, Marimba, working under Rick Rubin)
1992: The Southern Harmony and Musical Companion - The Black Crowes (Engineer)
1992: Core - Stone Temple Pilots (Producer)
1993: Vs. - Pearl Jam (Producer, Mixer)
1994: Superunknown - Soundgarden (Mixer)
1994: Purple - Stone Temple Pilots (Producer, Engineer, Mixer)
1994: Vitalogy - Pearl Jam (Producer, Engineer, Mixer, Organ on "Betterman")
1995: 100% Fun - Matthew Sweet (Producer, Mixer, Guitar, Piano, Electric Harp, Harpsichord, Clavinet, Mellotron)
1995: Mirror Ball - Neil Young (Producer, Mixer, Piano, Guitar, Background Vocals)
1996: Tiny Music... Songs from the Vatican Gift Shop - Stone Temple Pilots (Producer, Handclapping, Clavinet, Organ, Piano, Percussion, Tambourine, Handclapping)
1996: Evil Empire - Rage Against the Machine (Producer)
1996: No Code - Pearl Jam (Producer, Mixer, Piano)
1998: Yield - Pearl Jam (Producer, Mixer)
1999: The Battle of Los Angeles - Rage Against the Machine (Producer, Mixer)
(We won't talk about his nu-metal production credits for Korn, Limp Bizkit, and all of that crap, though)