The problem with the question is that I don't know if I have heard an amplifier I would want to keep for life. There are so many great audiophile and professional amps out there and I have not heard near enough yet. I do know one thing, it will a Class A or A/B design. Most every amplifier named in this post is either a Class A or A/B design. I have not owned any of the new Class D to T amps that for me are even in the running so far. I've owned over 40 different amplifiers so far and the only ones I seem to keep are all Class A or A/B designs.
Short list:
Pioneer
Sony
Tandberg
Nakamichi
Yamaha
JBL
Crown
NAD
Acurus
Music Hall
QSC
Carver
Audire
Hafler
BGW
Digital Phase
Audio Zone
Tripath
Bel Canto
Audio Analogue
Audio Flight
Creek
Atoll
Aragon
Quad
Threshold
Spectron
Parasound
AVI
Monarchy
Krell
Bryston
Unison Research
StereoKnight
