I am a huge DP fan, have been since they were unknown, saw them open up for another band in texas back in the day. It's excellent to see bands actually using there status for something decent. Although its hard to beat the first album which Dave "the stage" Williams can be heard on, because of his intensity, but I must admit there most recent album, which is Ryan McCombs from the band Soil. For those of you that are DP fans I suggest downloading some Soil tunes.
Shinedown is another band that was mentioned, that also does alot of fund raising for troops, as well as widows funds. There are plently of other bands that fit in the same genre that, have donated considerable amounts of time and funds, into the same cause, Damageplan, Nonpoint, Union Underground are all other supporters.
I heard Brent the lead singer of Shinedown, make a very pointed comment in reguards to questions about supporting there troops, and his answer was simple "What's the point of having a position where you hold people's ears, and having millions of people listen to your every word, if you don't use it to benefit anything". If i can find the interview I will post it up.