I had a good salesman at Porsche of Tysons, but don't remember his name. I came very close to buying there, but the only car they had in stock with sports seats was a 5K mile demo, and I really wanted a new one. However, they do support the local autocross/DE community (or so I have heard), so if you're in VA and going to track or autox your car, might be a good place to start.
I bought from Porsche of Arlington. The sales process was okay, no pressure or other sales shenanigans, but no huge discount either.
I had a bad experience with a salesman at Porsche of Rockville. I won't go into details, but he was a bit unprofessional.
I've had good experiences with Tischer Porsche. I don't know about the actual sales experience at Tischer, since I didn't buy my CS there, but their parts department is helpful and they give a pretty good
PCA member discount. Also, back when I had just started thinking about a Cayman, months before I was ready to buy, I stopped in one afternoon to just browse their lot -- I ended up talking with a salesman, and was invited to take a test drive
after explaining that I wasn't ready to buy yet. Also, Casey Parkin, a salesman at Tischer, is a member of this forum and a good guy to deal with.