At one time I was considering Fancy Rats as a pet. They are quite intelligent and fun but have life spans of 2 - 3 years. While I have very little empathy for other people I tend to grow quite attached to dogs and I decided I couldn't handle having 3 little animals of near dog intelligence that would die that fast.

http://www.martinscages.com/

Martin cages are considered by many small pet owners as the best designed and constructed cages available.