My brother and I went to Pev's Paintball a few weeks ago, as it seems to be the only Paintball place in the area. It is located on Rockville Pike, right smack in the middle of all the busy 355 traffic. It's on a small strip mall, so it can be hard to find for someone who is not from the area.
It's a small place and has a good inventory and the standard prices. Save yourself the long trip if you live in the area and don't buy at the outrageously priced places.