What's a good way to ask out a girl?

There is this girl that I've had a huge crush on...For about 7 months now. I really do plan on asking her out, since we've gotten really close and all, but the problem is that I don't know what's a good way to do so. I've been thinking of doing it face to face since it would probably mean more, but what if she finds it really awkward and gets uncomfortable. Of course, the other way is pretty much through computer or text message. Yes, it sounds wimpy but I've heard from my sister that some girls prefer this method because it gives them time to think and they feel comfortable. So I was wondering, from a female's perspective, which way would you prefer?