Not often enough! Honestly, I don't find many songs/artists these days that I really, really enjoy. Maybe 5 to 10 times a year? Not often... Interesting question, never really thought about it, I guess!
But that's the joy of it.....just at the point where I think I have discovered all my favorite artists something will slap me in the face out of nowhere. For example last year I discovered Boards of Canada, now I dunno how the hell I spent 27 years not knowing about them. Also Cinematic Orchestra, The xx, Air,Jon Hopkins and plenty more....I usually find random youtube related videos searches show me the way to hidden gems.
My mind gets blown on a daily basis. I feel like music as a whole gets better (noticeably) every single day, so there's always shit for me to fall in love with & become inspired by. The only time I don't find good music, is when I'm too busy // sidetracked to look.
About once a month I hear something that makes me search out the artist in more depth, a couple of the Youtube users I'm subscribed to regularly upload new stuff artists make available for free before they release the albums so I listen to pretty much everything they upload in one place, which is very handy.