Where should we stay in Washington D.C.?

My wife and I are going to D.C. next weekend. We want to figure out a great place to stay where we can see some of the cool sites and hit some of the fun areas. We looked at a cool hotel in arlington and another one just north of the white house. We wonder if it would be to far off being in arlington but it's right next to rosselyn metro and just south of georgetown. We are in our mid 20s and would love any input or thoughts anyone has. Thanks.