For the most part that means boring rather than interesting. Probably the best place to try going would be check out the Mosaic District in Merrifield. That would be near the metro stop (short walk if you like walking -- if you don't then take uber).

A few of my favorites...

Cuban - Cuba Libre
Italian - Al Tiramisu (it's a VERY small restaurant)
Indian - Rasika
Mexican/South American - Lauriol Plaza  
Spanish - Taberna del Alabardero

In the Tyson's area I like J. Gilberts for steak and seafood. By the way, they have an AMAZING Sunday brunch but be prepared to EAT.

I haven’t explored Tyson's much, hoping to change that in the new year. A lot of that area has built up, so many new places.  
 I’ve always been a fan of Patsys in Tyson’s corner, I frequent the back bar near the patio and you can ask for a menu for Randy’s (neighboring steakhouse) as well

 
I love Unconventional Diner, Dalphines, The Pembroke, Blue Duck Tavern (though I haven’t been in awhile) but so many amazing places I still need to try before recommending.
Kramers is a fun bookstore with a bar..great meet & greet spot  
On the other end of the city..Highly recommend walking the Wharf, anywhere you go there is lovely for a cocktail and appetizers. A lot of live music and events going on.

This is a small local restaurant chain that serves local produce, meats and poultry.  There's one right in Tysons.  Not cheap, but REALLY good!

Thank you so much to everyone who commented or private messaged me. Of course due to limited time, I was only able to visit a couple places, but now have a nice list of must sees. I had a great time in the capital and will definitely be returning before the end of the year!