Truthfully, a HS diploma is better than a GED looking at what you'd be getting in the process. Finishing HS would get you experience in a classroom plus a school social life.
Down the road, if you want to go to a state university then you'll need a diploma. A GED is all well and good, but you may also get sidetracked in the process.
Seriously, just finish school or else you'd get so far down on the college "waiting list" that it would be close to impossible to get on a college campus unless you have high SAT or ACT scores.
My best friend's sister got her GED from home and night school because she got pregnant, but it took her longer than it would have if she just would have finished school.