Thanks to Albert Porter I recently tried a number of isolation tweaks and of all things... the relatively inexpensive Mod Squad Soft Shoes made my CD's sound as if I'd upsampled them. Go ahead, try and take it from me! Also, I heard a Musical Fidelity HT600 amp at a friends, and never forgot it. It has endless reserve and never chokes, no matter how hard you push it, or what speaker you connect it to. It always retained its character no matter what cables or power cord I tried. I have never been happier with any audio product (with the possible exception of owning Duane Allman's Marshall 100 amp for about 5 years, but that's another story!) It made more of a difference than any interconnect or cable switch in getting me closer to the truth. I would think very carefully before "upgrading" it. Those two pieces combined with my Acoustic Zen Reference Silver interconnects give me that "musicians are in the room feeling", and a few chills occasionally.
Combinations that exceeded your expectations?
Putting the right equipment together is a real art--mixed with a good bit of dumb luck. Fortunately, experience sometimes does help get really stunning results by matching equipment from different manufacturers. I'd like to hear what equipment (like speaker/amp or interconnect/speaker cable or source/preamp) when paired together others found elevated their system to another level. Though entire systems are interesting, I'd prefer to narrow it to the juicyest equipment you've had the good fortune to pair up--and by all means name names.