During the short but amazing cherry blossom season in the DC area, I always make it a point to go to both the Tidal Basin in DC, and the Kenwood neighborhood in Bethesda. Both can get very crowded during peak bloom dates, but it's totally worth it!
The Kenwood area is a sprawling neighborhood filled with beautiful homes, and cherry trees up and down practically every street. It's quite a sight to behold and really amazing to walk through! Because parking is a major issue (which makes sense as it really is a neighborhood and it would be a nightmare for the residents if street parking was allowed everywhere), I usually walk to Kenwood via the Capital Crescent Trail starting in downtown Bethesda. It's an easy walk and I don't have to worry about parking at all in order to enjoy the cherry blossoms. You can't miss the Kenwood area from the trail - as you walk away from downtown Bethesda you will see a LOT of cherry blossom trees directly in front of you.
As you can see, it was a little overcast when I went this past weekend, but the trees were still full of flowers and really pretty. There were lots of people out enjoying the walk through the neighborhood streets and taking photographs. Even with the lack of parking, I highly recommend the Kenwood neighborhood as a major attraction on its own if you like cherry blossoms!