I've been researching on tournaments for Smash on the Wii U/3DS and here's what I've come up with so far:
Comics & Gaming
Wednesdays from 1900 to 2300
$5 Venue, $5 entry
7556 Gardner Park Dr, Gainesville, VA 20155 (30 min drive)
Message Ryan Bayerlein on Facebook
Super Smash Bros. UMD
Fridays at 1500 (Doors Open) 1900 (Sm4sh Singles Start)
Centreville Hall University of Maryland, College Park, MD 20742 (49 min drive)
Message on Facebook
Super Smash Saturday
Saturdays from 1900 to 2200
$2 Venue (Free w/ Setup), $5 entry
5 Willowdale Drive Unit 13-B Frederick, MD (57 min drive)
Message David Isobviouslya Goose on Facebook
Xanadu
Tuesdays from 1900
3921 Vero Rd. Baltimore, MD (1 hr 10 min drive)
Message Scott Robertson II on Facebook
Smash Till The End
Sunday at 1100 (Doors Open) 1800 to 2300 (Sm4sh Singles)
$10 Venue (-$3 w/ Setup), $10 entry
143 Zan Road, Charlottesville, VA (2 hr drive)
Message Dan Conn on Facebook
White Smash Rose
York, PA (2 hr drive)
I live in Reston, VA so that's why you see the amount if time it takes me to drive to the venues. A lot of these guys also do Melee tournaments, Xanadu especially.