We are hopefully going on our first cruise in June with our son, nephew, our twelve year old son and 8 year old daughter. Is there a line besides Disney that will please all?

I would suggest Royal Caribbean or Carnival - both have good kids' programs and lots of things to do for all ages. If the boys are sports-minded, I'd give the edge to RCCL, especially if you choose one of the new big ships, with their rock-climbing walls, minigolf, ice skating rinks, etc. But do check with a travel agent to be sure!