Some of the things I've always loved when listening to great audio, is the way instruments and voices just hover in the listening room, the way the treble works as a natural extension to the midtones, and not plays all the time no matter if it should or not. The way the bass plays different notes that are fast and easily recognizable, and starts and stops immediately when needed. The way the drums, cymbals and hi-hats are clearly "visible" in the soundstage, the recording rooms borders. The size of a human voice, the air in it, the hoarseness of some voices, the little throat sounds, the way "f" and "s" sounds, the attack on strings whether with bows, plecters or fingers, the difference between nylon and metal strings, the sound of a dobro, of a cello, of a piano, of a harp. The woodwork in different instruments, the crispness in brass instruments. A blues harp, a Hammond organ. I just love it

Edit: A Stratocaster...