It would be better to get your diploma.
Dont do the GED just to get out of the work of finishing high school.
That being said, a GED won't "ruin your life" like some have said.
It will make it harder to get into good colleges.
But if you go to a community college for a year or two, nobody will even care whether you had a diploma or GED.
And if you transfer from a community college to Harvard(quite possible if you get a high GPA in your community college classes), then nobody will care about your GED or your community college.
In other words, it is never too late to improve your academic standing. Most employers and grad schools, etc, will only care about your most recent schooling.