Basically music that's usually hated by a good amount of people, but yet you still take a personal liking to it for whatever reason, be it because it's "so bad it's good" or you actually think it's good because it manages to sound appealing to you.
One of the biggest examples for me of a specific band: Blood on the Dance Floor and Dahvie Vanity's side project Master of Death
A "scene" (you know, that off-shoot of emo that's like emo mixed with rave culture) band that's managed to outlive the days of MySpace by a large margin, usually combining electronic music and crunkcore (a genre often seen as "so bad it's hilarious"), and… I actually unironically enjoy a good number of their songs. Why? Honestly it's hard to explain. Now one song of theirs I like BECAUSE it sounds silly is "Yo Ho," it's basically a song that uses constant pirate metaphors for sex, but yet still throws in a line about being a "ninja," it's so ridiculous that I love it because of that reason. But songs like "Call Me Master," "Cruel Pornography," "Safe Word," "Where's My Wonderland?", much of the stuff off of Dahvie Vanity's "Master of Death" solo project album, and shit even one of their more disliked songs "Bewitched," I actually really like these songs unironically.
Also their cover of "Knock Out," originally by Lil Wayne (you know, from that brief stint where he did rock songs), IMO is actually much better than Wayne's version:
Next up is probably one that's gonna get arguably more of a "the fuck?" reaction: I actually rather like some of Justin Beiber's more recent songs. I should note however that at first I DIDN'T know it was Beiber who did these songs, I thought it was someone else. When I found out it was him my reaction was "oh wow good job Beiber, you actually made songs I like, just hope your attitude is better than it was last I heard about it…". In particular I actually really like "What Do You Mean?" and "Sorry"