I actually like most mainstream music. I adore Taylor Swift, but still appreciate Judas Priest and Metallica. I love the Temptations, but Lady Antebellum works for me, too.
About the only think I would say I have a problem with in mainstream music is the language used to describe women in rap and hip-hop. Women are not hoes, skanks, or bitches. You can get your point across without demeaning women. Unless, of course, that is your point. If so, it is far past time for women to stand up and put a stop to it. I don't mean by protests, etc. Money talks. If you are tired of women being demeaned, don't buy it. If it doesn't sell, it won't get made. Easy enough.
What type of music do you enjoy? Which type can you just not stand? Let me know!