I bought a pair of used Golden Tube Audio 40W monoblocks from a local audio store. They had been modified by Manley labs, I've had them for 2 years now and never had a problem. I'm fairly new to audio and have not listened to many different types of systems, but an old audiophile friend was extremely impressed with the sound of these amps and said they were a bargain at the price.
I read about the reliability issues - there is a long discussion on audioreview, and so a few months later I bought a second pair used on audiogon, thinking that I'd use them for parts when the first pair broke. Well, no surprise, idle amps beg for new speakers...I ended up getting a pair of used SL3s and set up a second system with the second pair of GTAs, and have used these for 18 months with no problems yet.
Maybe I've been lucky...but I highly recommend the GTA amps.