OK, I'll play.... Here's my list in chronological order:
2003/08/20 Radiohead (Merriweather Post Pavilion, Washington, DC)
2004/05/13 TV on the Radio/The Birdland/The Apollo Heights/The Six Parts Seven/The Hush (Supreme Imperial, Baltimore, MD)
2005/01/21 Colin Meloy (Iota, Arlington, VA)
2005/01/30 The Arcade Fire/Final Fantasy (9:30 Club, Washington, DC)
2005/02/24 Wilco (9:30 Club, Washington, DC)
2006/04/09 Neko Case/Martha Wainwright (9:30 Club, Washington, DC)
2006/08/03 Sleater-Kinney (9:30 Club, Washington, DC) [Farewell Tour]
2006/10/15 Jenny Lewis with the Watson Twins (9:30 Club, Washington, DC)
2007/05/04 The Arcade Fire/The National (D.A.R. Constitution Hall, Washington, DC)
2007/07/26 The Swell Season (9:30 Club, Washington, DC)
2007/07/28 The White Stripes (Patriot Center, George Mason University, VA)
2007/10/25 Jens Lekman (Black Cat, Washington, DC)
2008/06/11 R.E.M./Modest Mouse/The National (Merriweather Post Pavilion, Columbia, MD)
2009/07/30 My Bloody Valentine (The National, Richmond, VA)
Those are the ones that stand out. They're each special, magical shows that I hope I never forget.
Honorable Mentions:
2002/04/30 Garbage/Abandoned Pools (9:30 Club, Washington, DC)
2003/10/08 R.E.M./Pete Yorn (Patriot Center, George Mason University, VA)
2004/04/01 The Crystal Method/DJ Hyper (9:30 Club, Washington, DC)
2004/04/22 Sleater-Kinney/The Thermals (9:30 Club, Washington, DC)
2004/06/01 Beulah/Dios (Black Cat, Washington, DC)
2004/06/09 Wilco (9:30 Club, Washington, DC)
2004/10/14 Mission of Burma/Channels (Black Cat, Washington, DC)
2004/12/08 Pixies/TV on the Radio/The Bennies (D.A.R. Constitution Hall, Washington, DC)
2005/03/23 Robyn Hitchcock/Meredith Bragg (Black Cat, Washington, DC)
2006/01/28 Colin Meloy/Laura Viers (Birchmere, Arlington, VA)
2006/03/29 Stellastarr*/Editors (9:30 Club, Washington, DC)
2006/10/15 TV on the Radio (9:30 Club, Washington, DC)
2007/07/14 The Decemberists with the Baltimore Symphony Orchestra (Merriweather Post Pavilion, Columbia, MD)
2008/03/18 God Is An Astronaut (The Ottobar, Baltimore, MD)
2008/04/13 Colin Meloy/Laura Gibson (9:30 Club, Washington, DC)
2006/07/15 Mission of Burma (Black Cat, Washington, DC)
2009/01/18 Moby (DJ) (9:30 Club, Washington, DC) [Inauguration Night]
2009/06/08 The Decemberists/Andrew Bird/Robyn Hitchcock and the Venus 3 (Merriweather Post Pavilion, Columbia, MD)
2009/08/28 The Flaming Lips/Explosions in the Sky (Merriweather Post Pavilion, Columbia, MD)
2009/11/30 Pixies/Jay Reatard (D.A.R. Constitution Hall, Washington, DC)