Vintage Integrated Amplifiers With Great Sound

Unusual situation is going to require me getting an integrated amplifier. Buying something that will satisfy me in a current range of production is simply going to cost a lot more than I want to spend. 

What vintage integrated amps from, say the 70's-80's-90's can be found at relative bargain prices, but provide really good sound quality? 

Any thoughts or recommendations appreciated. Thanks in advance.