Electronics: OPAMP tests into a 270 ohm load

A friend was modifying a cheap headphone amp, and was wondering which OPAMP would work the best.
So I created a similar circuit and measured several different OPAMPS loaded with 270 ohms as a 'typical' headphone load.
Note: Don't only look at the headline THD figure - also note the harmonic distortion even for some that measured well.
Measurement parameters:

PSU: 15 - 0 - 15
Gain: 2.2
Output: 2.7V RMS
Load: 270 ohms