I probably like the looks of the Harmon Kardon Citation -The Receiver the best of the ones in my stable. Very elegant, sophisticated, "classy", with beautiful wood inlay in the top and detailed incised-patterned material on the sides. Both classic and modern at the same time; timeless, in a way.
Almost as nice is the Marantz 2275 in a BLACK wooden case.
Honorable mentions go to the Pioneer SX-1250 and SX-828, Marantz 2285B, Luxman R-1040, and Sansui 9090. The big Sansui G-series amps are also beautiful, but sometimes a wee bit too much like "bling" for my tastes.