I got a little Yamaha (lightly used) I picked up last winter.... it's a nice boat, it uses jet ski engines and drive units so it really turns on a dime, and replacement parts/upgrades are very easy to find. says it seats 4-6 but i don't let anybody on the bow when i'm driving. It's great on gas, and hasn't cost me too much... plus it's small enough if i really need to i can tow it with my civic. also because of it's size it can get up and scoot, my bud has a really really big fountain on the lake (michigan) we usually go out on the lake with his boat, and put arround the river (grand river) with mine... acctually mine gets used more, his has 3 454's punched out and supercharged... it costs him $$$ just to fire it up. although i haven't tried it yet another guy in his harbor has one very simular to mine made by ski doo and said if he keeps it to a driver and spotter he can tow a "fit" skier.
one of my neighbors has a small Baja i think he said it was 24 foot, it's a nice boat has a 6 cyl in it. it's good for medium sized lakes.
I also have two Kyaks (sp) 1 sea 1 White water, and a Laser (sailboat) most of these I have picked up used, and repaired small problems and in the long run saved $$$
and we wont even get into the model boats i own!