http://www.barnesfoundation.org/ In Philly

http://www.fodors.com/community/unit...and-philly.cfm

There's my trip report for my DC and Philly trip last year which may help. Click on my username for more DC trip reports.

Thank you all for your suggestions, links and great trip reports, you guys are the best.
We will definitely be eating the crab! And checking out Georgetown.

I love the Morris House Hotel, but it doesn't look like it has any twin rooms and this is a trip with a friend, not DH, sadly.

Thanks longhorn for the day trip idea, good to know we can do a day trip like that using public transportation.

flpab, I will ask St.Cirq over in the Lounge, although with all the suggestions I have already got I could be busy for 2 weeks!

An option I like in Philadelphia is the Independent Hotel:
http://theindependenthotel.com

thank you kja, I think that is the perfect hotel for us. If my friend approves, it'll be booked tomorrow.

Have you stayed there?

Yes, I stayed there just over a year ago and found it very comfortable. Here's the review I posted on TA:
http://www.tripadvisor.com/ShowUserR...nsylvania.html

DH and I loved the food and atmosphere at Old Ebbitts Grill near Capitol. Very dark, rich wood interior.

Places:
Memorials and monuments are my favorite
Ocean City for a quick beach trip
Georgetown

Food:
Food trucks (http://foodtruckfiesta.com/)
Cafe Asia

Music:
iota club in Arlington

Thank you showtime2 and iheartrice, I will look into those suggestions!

I agree with many of the above: Georgetown for food and cute shops; The museums on the mall. The Holocaust Museum is a must see! Arlington Cemetary of course. For a quick road trip- I loved both Annapolis and Baltimore when I lived in the DC area. If you had time for a longer side trip: Williamsburg and VA beach I enjoyed more than Ocean City.
One of my favorite restaurant years ago was the 4 P's (Irish Pub)on Conneticut Ave.

I believe that the 4 Ps (aka 4 Fields) Pub, which used to be in Cleveland Park on Connecticut Ave., has closed.

Hello! I just saw this thread and I know I'm late to the conversation, but I noticed an absence of attention to Capitol Hill--close to Union Station and the Smithsonian and full of great things to do, including wonderful restaurants, bars, and music. I hope you saw this article in the NY Times with some highlights of the neighborhood:
http://www.nytimes.com/2014/05/18/tr...n-dc.html?_r=0

I love Mt. Vernon, especially the view over the Potomac. It is wonderfully peaceful and historic and a great place to wander around.

Oh, am just seeing this now, thank you so much abbydog! Have bookmarked that article and am also printing it off now to read.
cferrb, am I right in assuming one can get public transportation to Mt.Vernon? (thanks for the tip)

My friend and I are starting to get excited now about our trip, 5 nights in DC and 4 nights in Philly!
Another friend is there right now with her husband and loving it, I will get the full story and recommendations when she returns.