It depends on what kind of non-metal I'd be suggesting, because I know that more than a couple of my non-metal recommendations have been things people here have enjoyed.
I know for a fact that Onder liked Jesse Sykes & The Sweet Hereafter, I know KafkaX liked First Aid Kit, pretty certain there were people who liked Cinnamon Chasers (if not here then I know on a few other metal sites people who liked them and only found out due to me introducing them), Genelec & Memphis Reigns is probably the most well received rap recommendation I make anywhere, etc.