My favorite, Kitty O'Shea's has moved form Arlington to Upper Northwest, DC, near American University. I haven't been yet but hope to soon.
Summer's Restaurant in Arlington is a long-time pub. Less friendly than Kitty's but they have an English breakfast for the ex-pats.
The Pour House is on the Hill. I've been there only once but it seemed ok, but it was for a Monday afternoon game, so I don't know if they are open for Saturday/Sunday mornings.
The Lucky Bar is in "downtown" DC and is pretty good. Unfortunately for me, my first time there, we lost to Spurs 4-0 in the FA Cup, so that did not give me good memories.
What I don't know is if any of these pubs show the online only Fox Sports games (foxsoccer.tv). Since many of the games are available only that way, a pub that shows those games would move up the list quickly.
Kitty O'Shea's, 4624 Wisconsin Ave., NW, DC
Summer's Restaurant, 1520 N Court House Rd., Arlington, VA
Pour House, 319 Pennsylvania Ave., SE, DC
Lucky Bar, 1221 Connecticut Ave., DC