There is nothing wrong with the Gin Blossoms, Madonna, or the Cardigans. OR A-Ha! I listen to all of those proudly.
I listen to Hole too (and actually think Celebrity Skin is a great album..."Northern Star" is their best song hands down) so THAT is a guilty pleasure.
Nelly Furtado.
Oh, and Rongi, "Walking on Sunshine" is by Katrina and the Waves, unless the Pretenders did a cover I don't know about. That's one of my favorite songs too and I feel no guilt about that whatsoever.