I currently use a top-freezer fridge for fermentation. Had to install of "shelf'' on the bottom for support, but it fits (2) 6.5 gal carboys easily.
I previously used a chest freezer and I like the fridge because its much easier to move carboys in and out. Its also easier to see whats going on inside (in a chest freezer you can only see the top).
Homer: Im feelin low, Apu. You got any of that beer that has candy floating in it, you know, Skittlebrau?
Apu: Such a product does not exist, sir! You must have dreamed it.
Homer: Oh. Well then just gimme a six-pack and a couple of bags of Skittles.