NAD, because of their price to performance ratio. Same for Rega and Denon. Marantz for my roomate's preamp that I got to use for two years, and their slightly to much higher end approach to the price to performance math, and Linn for my best friend's turntable that blew my mind and got me interested in the high end in the first place.

Trey

Benchmark, Transparent cable, and PS Audio because they are so very competent and professional in every dealing I have ever had with them. In a related field...Channel D Software (creators of Pure Music) for their prompt response to questions.

A few come to mind:

Mark Levinson (Before they sold out to Harman)
Hovland (even though they went out of business, they produced some of the best tube gear around IMHO.)
Boulder
Classe'
EMM Labs
Wadia
EgglestonWorks
Acoustic Zen
GIK Acoustics
Pass Labs
VTL
Dynaudio (drivers)
Morel (drivers)

Mark Evans

I have had very few break downs and thats the time you find out who your friends are . There has been very little need to contact manufactures so my experience with them has been minimal .
The two I do hold in high esteem are Ayre and A.R.C.
If Areil had asked who don't I respect I could give a much longer list .
Tim

i have always been impressed with the gear made by simaudio. any piece of equipment i have ever heard from them has sounded great and always looked very good in an understated way. their reputation for quality is also very good.

Ariel ya right , and have the audio community including friends and club members pounce on me like a big wet dog . Maybe one of the posters below will have more stones . Tim

For me it's Audio-Research, Ayre, Conrad-Johnson, Klipsch, Dunlavy, JBL, Advent, Scott, Fisher, Dynaco, KLH, SAE. I know some are gone but not forgotten.