I have a pair of Audio Technica ATH-M50s. They're pretty good, but I'm hoping there's better quality to be had for less than R2500. They have to be closed-ear, as I want to use them at work. Which is why most Sennheisers cannot be considered. Comfort will also be important, as will a non-fatiguing sound.
Of course if the recommended headphones will prove difficult to drive, feel free to pitch in on headphone amps too
Of course if the recommended headphones will prove difficult to drive, feel free to pitch in on headphone amps too