I'll second Marty's recommendation of the mid 80's Jeanneaus. I got a 1986 Jeanneau Sunshine 36 with a factory option sugar scoop a few years back and it is a great boat. We too have a family of 4 (girls 12 & 17) so the three cabin layout gives everyone their own space and room for the kids to invite friends along. The sugar scoop is very handy and most of the 36's I see have them. The Sunshines can be had for $45k - $60k depending on the condition and accessories. While the girls were away at camp last summer my wife and I spent three weeks cruising Desolation Sound and the Sunshine was extremely comfortable to live on. A great light air boat too.
1986 Jeanneau Sunshine 36+