I really like Iris containers. They're a little more $$$ but they have completely flat bottoms so it's super easy to clean them. Plus the plastic they're made of is indestructible.
- For my babys I use the "Shoe Box": 13" x 7-1/2" x 4-1/4" h
- For my colubrids, small male boas, and male balls I use the "Boot Box": 22-1/2" x 14-3/4" x 5-3/8" h
- For my larger male boas and smaller female boas and female balls I use the "Long Underbed Box": 35-5/8" x 18-1/4" x 6-1/4" h
Here's a link to "The Container Store" where you can buy Iris boxes.