United and Delta (by acquiring NW) are the only remaining US 747 operators, and they all have the 400s. NW did have a 200 they used for charters until a few years ago.

There are a ton still in cargo operation, of course, and a few for special operations. The VC-25 is a heavily modified 747-200, but you need a invite from the President to ride it.

NASA was using an ex-AA 747-100 to ferry the Space Shuttle. NASA also uses a 747SP as a flying observatory.