If you could just pick one instrument that you think sounds best on your speakers

What would it be? I love my OHM 5000s. The instrument of my choice would be the synthesizer. I'm now listening to EL&P's songs Tank and Tarkus on CD. Ive just played them 3 times because it gives me good frisson. (Other thread). In the opening of Sade "Smooth Operator" the synthesizer sounds like its notes are moving all around in the room. It's the same with Tears for Fears "The Working Hour". 
So if you could just pick one instrument that your speaker plays the best at. What would it be? I'm sure this would be a tough question for some members because there are many great speakers that do very good at all music. It might also be one instrument you like hearing best anyway. So what would be your choice?