Well I find this an interesting topic, because I have one too, and have gone 'round and 'round about how to stock it. You can definitely keep 3-4 freshwater puffers, as they are only about 1.5 inches long, but not much in the way of tankmates as they are fierce. They are so tiny that they don't make for a very interesting tank. My favorite setup involves school of harlequin rasboras and one of cardinal tetras, maybe a pygmy cory cat or two and some shrimp. In my heavily planted 10-
gal this is fine, as the plants are the focus. Otherwise it gets kinda boring. You can definitely also keep rams, as they stay small. A dwarf gourami is great (mine allows NO tankmates, unfortunately, but not all are like that) and there is always the betta with some white cloud minnows. You can go with guppies, also, or a school of the smaller tetras. I would stay away from mollies/platys/swordtails as they generally get bigger than is comfortable for that size tank, not to mention babies. Then you have the shell-dweller dwarf cichlids (very interesting; I plan to try this next) that can do very well in a 10-
gal. Rams get my top vote right now, as they are usually available (never seen the shellies offered at the
LFS) and are quite beautiful, with long-finned varieties being commonly seen around here lately. You can put them with a small school of neons or any of the small tetras. Avoid zebra danios; they require a lot of room to swim and are not happy in a 10-
gal. You can find some small plecos that will live comfortably in a 10-
gal, or go with otocinclus cats for algae cleanup. There are probably more No-No's than recommendations, however, and it is easy to go wrong with stocking a 10gal. Sorry for the diarrhea of the keyboard - your'e probably sorry you asked, now!