Some of this stuff, like Alanis, isn't "guilty" pleasures for me. I think she was an awesome writer. Jagged Little Pill has to be one of the best titles of all time. "Head Over Feet" is a wonderful love song, and at the other end of emotion, "You Oughta Know" is about as good as you get for "you broke my heart" songs as well as being so nicely complex musically.
My guilty pleasure is '80s Madonna, with her pipey perky voice. I just really like it.
I was in a piano bar, and they called for the veterans to hang back, and I hung back but my friends pushed me to stage, and they played Lee Greenwood's "God Bless the USA" while four of us stood up there before a standing crowd, and we were kinda embarrassed but took it, and I've had a warm place in my heart for that song ever since.
The Byrds' "Kyrie Eleison." Mr. Mister's "Kyrie."
And for fogy music: The Cyrkle. I don't expect y'all to know them. I just liked the flow of their songs, even if they are kinda silly and pop.