Do!Aqua 3 gal. Cube, 10x10x10, $49.95 (ADGshop)
Mr. Aqua 3 gal. Bowfront, 12x7x8, $26.99 (Marine Depot)
Mr. Aqua 7.5 gal. Cube, 12x12x12, $49.99 (Marine Depot)
Aqueon Evole 4 gal., 10.5x10.5x11.5 $50 to $60 (Petsmart or Petco) (Includes light and filter)
Fuval Spec 2 gal., 7.25x9.25x10, $50 to $70 (Petsmart or Petco) (Includes light and filter)
TruAqua Bowfront 3.5 gal., 12x8x8, $25.99 (TruAqua)
There is others, but price maybe more than you want. GLA, Penn Plax Radius 3.5 gal., and Finnex (seems out of stock).