Well, a GREAT place to view the fireworks is from the river in DC...if you know anyone with a boat, and you can snag an invite, go for it. In another lifetime, my dad and I had a couple of different boats...so I did the 4th of July thing every year for about 8 years.
You get a great view of the fireworks, and you don't have to deal with the million or so people on the mall. And, you can sit in the AC if it's hot...which it ALWAYS is.
I also saw the show they did after the Gulf War...they were shooting stuff off from 3 different locations at once...truly awesome.
Unfortunately, those days are over for me, unless I hit the lotto. But, like I say, if you get the chance, you shouldn't turn it down.
There are areas here in No. VA that are good, but it's not like everybody doesn't know about 'em, so expect a crowd.