Anyone have tips for a family budget friendly good seafood restaurant in/near DC? A buffet would be good, as long as it isn't bad quality.

DC is not known for its seafood and the places that have good seafood in DC are not budget. Would you consider another type of food?

Yeah, "budget" and "seafood" don't really go together in the DC area. You could ask on the DC section of chowhound.com, which favors budget-friendly but good places, just in case there's some out of the way joint.

A lot depends on what exactly you mean by "seafood restaurant." The best-known regional specialty in the area is Maryland blue crab, but the places that serve it cheapest are often more like roadhouses or diners in decor, rather than "restaurant." This is related to the fact that hard shell crabs, the cheapest way they come, are quite messy.

One place I'd recommend is Cap'n Billy's -- a bit of hike from D.C. proper, but has a picturesque location on the Potomac and makes for a nice leisurely weekend drive:
http://captbillys.com/Home_Page.html

Another well-known place that is on my list to try is Cantler's, near Annapolis: http://www.cantlers.com/

If your hearts are really just set on a buffet, and you're not overly picky foodie types, then you might consider Phillips, which is in D.C. proper, on the Southwest waterfront: http://www.phillipsseafood.com/ A lot of tour groups go here and love it. However, its reputation has fallen among locals in recent years, in part due to their increased importation of seafood from abroad. You can see the mix of reviews here: http://www.yelp.com/biz/phillips-fla...ill-washington At a minimum, it has a nice waterfront location going for it.

Good luck!

Phillis is awful! save your money. jimmy cantlers is great-right on the water, but a good 45 minutes outside DC and definitely not cheap.
I did think of crisfields on Georgia Ave in Silver Spring, MD still has good seafood. it's about a 20-30 minute ride outside downtown DC. Again not budget and not a buffet.

Phillips was awful in the 1980's, lol! I dare say it never had much of a reputation among locals.

RED Hook Lobster Pound imports Maine lobsters and sells lobser rolls from a mobile truck in D.C.
http://redhooklobsterdc.com/

Hank's Oyster Bar at 1624 Q St. NW is a full menu seafood restaurants. Prices are $15 to $20 for entrees. Quality and atmosphere is very good. If weather is pleasant, Hank has a patio. Hank offers the best of the local product. i have enjoyed every time I have visited.

Red Hook Lobster truck is great! Hanks is also good.

Big Hank's fan too. I think the OP said they were traveling with kids and elderly parents. If so, I'd pass on Hanks. They don't take bookings and the wait can be long.

The lobster rolls from the truck are good but it's often a long line and they cost $15, which may not really fit the OP's request for a cheap option.