Originally Posted by
Charlie Ky
So really none of them because we don't know much about you. I would be very careful dealing with Craigslist so you don't get any stolen bikes or bikes that need a lot of work. Make sure you can test ride the bike and make sure it fits and again doesn't need a lot of work. If you are new to all of this you might consider going to your local shop and trying to find something new of quality, you will get support for the bike and a warranty on it. In many cases you will also get a tune up for free.
If you are stuck on buying used I would see if you can find something that is likely to fit and see if you can meet at your local shop and if they can look over the bike before purchase.