Seasons on Circuit Ave has mediocere food with some good selections for kids. The best thing is a big attached game room where the kids can play video games, pin-ball, and air hockey type games. They also serve sushi that has been very good every time I've had it. It can get a little loud during sports games that they show on many TV's, but it's all good fun. A very short walk to the carosele (did I spell merrygoround OK?) It's a good location for kids. The beach is right there too for a swim.
Depends how young the "kids" are. Up till age 10 Slice of Life may not be appreciated although we like it a great deal. Park Corner Bistro is probably as good but also not cheap. I am boycotting Nancy's, but if you want to eat near the docks try Coop De Ville which we like better anyway. Best value choices in OB would be Offshore Ale Company and Sharky's Cantina (we prefer the Edgartown loaction) . Except for Sharky's, Edgartown is generally more expensive and more dinner oriented, but Among the Flowers Cafe is very good. Most of these places have web sites so you can check out the menus before you choose.
Park Corner Bistro
20 H Kennebec Ave, Oak Bluffs, MA 02557
Slice of Life
50 Circuit Ave, Vineyard Haven, MA 02568
Among the Flowers Cafe
Mayhew Ln, Edgartown, MA 02539
266 Upper Main St, Edgartown, MA 02539