The GPA Myth
"It doesn't matter which classes I take in high school, as long as my grade point average is high."
If you're playing the GPA game and taking a light schedule that isn't challenging, it will catch up with you at the college level very quickly. One of the things admissions officers pay attention to, besides GPA, is course selection throughout high school and especially senior year. They like to see students have momentum going into the freshman year. If you sit back your senior year, it's hard to recapture that momentum.
Course selection can also affect admissions test scores. If you just go for a good GPA, you'll be less prepared for college and will score lower on entrance exams.