I always thought these were the dumbest things but then I got one. It can be adjusted to fit every member of the family except me, it's totally maneuverable and really simple. I can even ride it without too much trouble.

This one is the most fun for a quick zip around the neighborhood. It's a little small for me so it's easy to swing a leg over the top tube but then it's got a really long seatpost so it actually fits me. i like a coaster brake for riding around the parking lot with the kids, too;

Then there's the 10' long 75lb monster that I pick the kids up from school with. Dumbest waste of boat anchor fixins ever but it's the bike that see the most use around here;