My favorite place for takeout sushi near Cameron Station (where I live) in the West End of Alexandria is Taste of Asia. Easy pickup when bringing sushi for dinner with my Overlook friends. Much easier to get to than Yamazata at the intersection of Little River Turnpike and Beauregard. Although they make good sushi too.
Spicy Tuna, Alaska, and Godzilla rolls are my current favorites. The sushi, Chinese, and Thai options do not disappoint. Check out their menu at tasteofasia-alexandria.com.
Taste of Asia is located at 362 S. Pickett Street, where Home Depot is located. Taste of Asia is located next to Cameron Station, so ordering to pick up for me is 15 minutes. Would be the same for Overlook.