Simply put, to call Faith No More solely a metal band is highly inaccurate because they play so many different genres. And now that I think about it, my favorite record is probably King for a Day, Fool for a Lifetime; that's not to say their other albums are bad. In fact, they don't have a bad album to their name, although I found Angel Dust incredibly hard to get into as it takes the Faith No More norm of being insanely weird and ups it many, many times. It was a grower, and a rewarding one at that.
I vastly prefer the band with Mike Patton on vocals as a opposed to Chuck Mosely who sang on the first two albums. Patton conveys greater sense of a emotion, especially because he's less monotone and because he exercises a vast array of unique styles. One second he'll be emotionally serenading you, the next rapping, and the next barking like a dog through the mic. He's one of the most diverse and unprecedented vocalists in all of metal, even in any genre of music period.
So, what song will give you a feel of what Faith No More is like? Honestly, that's impossible to do with a single track. I can, however, post one of my favorite songs from the band. Choosing it wasn't easy, as pretty much any song ranges from good to excellent.
This song doesn't even begin to sum up Patton's vocal styles or the genres the band plays, but it's a good 'un. Actually, this one is very, very tame for the band.
Faith No More - "Digging the Grave"