This should help out many of you. Each category is sorted alphabetically. Remember, not all of the brands on here are still being manufactured.
Head units
----------------------
Audiophile Grade
Alpine F#1status (no longer made)
McIntosh Labs
Pioneer Premier (flagship models)
Nakamichi (tape decks)
Pioneer Stage 4
Good
Alpine
Blaupunkt
Clarion
Clarion ProAudio
Denon (old)
Eclipse
JVC
Kenwood Excelon
Nakamichi
Panasonic MXE
Pioneer
Pioneer Premier
Sony Mobile ES
Phase Linear
Pioneer
Questionable
Jensen
Kenwood
Panasonic
Sony
Avoid
Audiovox
Boss
Dual
Jensen (older models)
Sanyo
Valor Multimedia
Amplifiers
----------------------
Audiophile Grade
Arc Audio
Audison
Brax
Eclipse
Esoteric Audio
Genesis
Harrison Labs
Helix
Incriminator Audio
McIntosh Laboratories
Orion (classic GS, HCCA, SX, GX, and XTR series)
Precision Power Inc (PPI) Art and AM series (classic)
Rockford Fosgate (early 90s, Punch and Power series)
Sundown Audio
Tru
US Amps (old models only)
Xtant
Zapco
Good
a/d/s
Alpine
American Bass
Audioque
Atomic
Autotek
Avionixx
Cadence
Cerwin Vega
Concept
Coustic
Crossfire
Diamond Audio
Directed (DEI)
Elemendal Designs (eD)
Elevation Audio
Hertz Audio
HiFonics
JBL
JL Audio
Kicker
Lightnihg Audio
Memphis Audio
MMATS
MTX Audio
Orion
Phoenix Gold (classic US-made)
Planet Audio
Precision Power Inc (PPI)
Rockford Fosgate
SoundStream
US Acoustics
Viper
Questionable
Alphasonik
Audiobahn
Crunch
dB Drive
Earthquake
Interfire
Kenwood Excelon
Lanzar
MA Audio
Massive Audio
Phoenix Gold (newer)
RD Audio
Tsunami
US Amps (newer models only)
Avoid
Bazooka
Coustic (old AMP series)
Jensen
Kenwood
Kole
Legacy
Optimus
Power Acoustik
Pyle
Pyramid
Sony
SPL
Visonik
Volfenhag
Main Speakers
----------------------
Audiophile Grade
Accuton
Alpine F#1status)
Bravox
DLS
Dyn Audio
Eton
Focal (flagship line)
LPG
Morel
Rainbow
ScanSpeak
Seas
Vifa
Good
a/d/s
Adire Audio
Alpine
American Bass
Arc Audio
B&C
Beyma
Boston Acoustics
CD Technologies (CDT)
Cerwin Vega
Crystal
DB Drive
Diamond Audio
Eclipse
Earthquake
Eminence Audio
Focal
Hertz Audio
Hybrid Audio
Focal
Fusion
HI-VI Research
Illusion Audio
Image Dynamics
Infinity
Interfire
JBL
JL Audio
Kicker
LPG
Massive Audio
Max-Fidelity
MB Quart
Memphis Audio
Peerless
Pioneer
Polk Audio
Quantum
Resonant Engineering (RE)
Rockford Fosgate (RF)
Usher Audio
Visatron
Zapco
Questionable
Kole
Phoenix Gold
Planet Audio
Power Acoustik
Powerbass
Avoid
Audiobahn
Boss Audio
Crunch
Dual
Jensen
Kenwood
RD Audio
Sony
Soundstorm
SPL
Subwoofers
----------------------
(Due to the constantly changing nature of the subwoofer market, and the fact that there are numerous subcatagories for competitors, an Audiophile Grade catagory has not been included for this section.)
Good
Alpine
Alumapro
American Bass
Arc Audio
Ascendant Audio
Atomic
Audiopulse
Audioque
Autotek
Boston Acoustics
Bravox
CD Technologies (CDT)
Cerwin Vega
Concept
Coustic
Crunch
Crystal
DB Drive
DC Sound Labs
Diamond Audio
Digital Designs (DD)
DLS
Dyn Audio
Eclipse
Fi Audio
Focal
Funky Pups
Fusion
Hertz Audio
HiFonics
Image Dynamics
Incriminator Audio
Infinity
Inhuman Audio
Interfire
JL Audio
Kicker
Lightning Audio
Massive Audio
MB Quart
Memphis
MMats
MTX Audio
Onyx Audio
Orion
OZ Audio
Pioneer
Planet Audio
Polk Audio
Powerbass
Quantum
Rainbow
Resonant Engineering (RE)
Rockford Fosgate
Shok Industries
SSA (Sound Solutions Audio)
Sound Splinter
Stereo Integrity
TC Sounds
Treo
Xtant
Questionable
Adire Audio
Coustic
Earthquake
Elemental Designs (eD)
Elevation Audio
Kicker Solobaric square subs
Kole
Phoenix Gold
Power Acoustik
RD Audio
SoundStream
SPL
Avoid
Alphasonik
Alpine (Type-E series)
Audiobahn
Bazooka
Boss Audio
Dual
Jensen
Kenwood
MTX (6000's and under)
Pioneer (lower models)
Power Acoustik
Pyle
Sony
Soundstorm
Volfenhag
Wiring
-----------
Good
American Bass
Audiopipe
Audison Connect
Directed
Hooker Audio
Kicker
Knukonceptz
JL Interconnects
Phoenix Digital
Scosche
Streetwires
Tsunami
Questionable
American Bass
Audiobahn
MA Audio
Avoid
Raptor
Batteries
---------------
Good
Deka
Duralast
Eagle Picher
Everstart (Maxx batteries)
Exstatic
Interstate
Kinetic
Northstar
Odyssey
Optima
Powermaster
Scosche
Sears Die Hard Gold and Platinum series
Stinger
Tsunami
Avoid
(none placed here yet)
Alternators
-------------------
Good
DB Electrical
DC Power
H/O alternators
Lestek
Mechman
Ohio Generator
Powerbastards
Powermaster
Stinger
Wrangler
Questionable
Excessive Amperage
Iraggi
Motor City Reman (MCR)
Avoid
(none placed here yet)
Dash Kits/Install Accessories
---------------------------------------------
Good
American International
Metra
Questionable
Scosche
Avoid
(none placed here yet)
