Benchmark DAC2 is amazing and so versatile. It maybe a little expensive for a desktop (like I use) but I do not see myself changing this DAC for the next 20 years. I have a tuner hooked up, cable TV, and a USB computer for my FLAC's. The speakers are KEF LS50's powered by Parasound A23 amp.
I had Audioengine A2 speakers for a long time thinking that for a desktop office system it would suffice. But it was not really satisfying. So I changed to the new configuration and it is stunning. I love to sit and work at my office now.