Antenna Setup for Washington DC

This is by far the best bang for the buck. My next choice would be either the Channel Master you linked to or this. The Clearstream 2 is a UHF antenna & may not work well for 7, 8 & 9.

+1 on the antenna DigitalRules linked to. If you're not comfortable with craigslist or if n/a, order it from amazon or walmart.
http://www.amazon.com/RCA-ANT751-Out...B5C/ref=sr_1_1
http://www.walmart.com/ip/RCA-Suburb...-Mast/10828410

Aim it compass direction of 325° or roughly NW. If the DirecTV coax cables have any splitters, multiswitch boxes or other equipment in the line, remove any of that, if present (you can reuse the existing ground block). If you need a splitter, use a regular coax splitter from radioshack, walmart, home depot, etc. If you remove a multiswitch and need to splice the cables together, use a barrel splice.

I would get an Antennacraft HBU22 from Radioshack and perhaps a Winegard 269 preamp. A little more gain would give you a better shot at Baltimore in addition to DC. Maybe add a rotor unless you can find a sweet spot. Another similar antenna, Winegard 7694 would have a bit better build quality. But that RCA 751 should work fine for just DC unless you are in a problematic reception area. And if more gain is needed for Baltimore, the next step up would be HBU33 or 7696.

A 751 for $22 is a steal. Get it if you can.

Otherwise, get the C2V instead (or get the VHF upgrade kit for an existing C2) if you like the really compact antennas.