At least IMHO:
'Til Summer Comes Around Keith Urban & John Mayer.
In this song, their voices & guitar tones really seem to complement each other nicely. I especially like Mayer's tone with the Dusenberg starting about 4:20, but Urban's playing is really nice too. Guitar wanking
without forgetting the melody.

Apologies for not being able to find a link without the darned ad at the beginning.
Chip