I haven't seen anyone post anything, so here are mine.
1) Coachella (first night), May 1st
highlights: The Pixies, Kraftwerk
2) Pixies @ the Aragon Ballroom, November 13th
3) Air @ 9:30, April 8th (1st night)
4) Social Distortion @ Nation, October 18th
5) PJ Harvey @ 9:30, October 13th (A lot of people said this wasn't great, but I was blown away by her and her band...great energy from them, lousy response from the audience)
6) Curiosa @ Merriweather, August 6th
highlights: Interpol, the Cure
7) The Shins @ Black Cat, February 11th (2nd night)
Bob Mould @ Birchmere, January 9th
9) Supergrass (10th anniversary) @ 9:30, Sept. 29th
10) Face to Face farewell tour @ 9:30, August 17th
First off, I tried not to include the Pixies more than a couple times, even though I saw them 7 times and they could have easily have taken up most of the top 10. Coachella for me was an incredible experience and seeing the Pixies walk out together onstage in front of 50,000 people went down in rock history as one of the 100 most important moments. I know I'm sounding dramatic there, but to see it and be there really was something. It really showed how powerful music is and I've never seen an audience so respectful and in awe. And Kraftwerk's set was just surreal. The Pixies stole a lot of thunder, but Kraftwerk were probably still the best band of the day.
Second, there were many amazing shows this year but I had to pick the ones that were the most memorable. Honorable mentions include the Peaches 9:30 gig and the Hives. The biggest disappointment was Morrissey in Chicago at the House of Blues. All in all though, 2004 was a great year for live music.