MODARTT Pianoteq 5 Software Piano Instrument
Was a little sketch because it's not really modeled off a real piano. However, I love the CPU efficiency of this plug-in (unlike Kontakt) and the customization options (I have the standard edition right now; can't imagine what messing with overtones and stuff would be like). So yeah... while the default sound isn't mind-blowing (sounds like a piano), you can get some mind-blowing sounds going really quick... =)
Modeled piano plugin synth. No samples used.