I started breeding bugs for the dragon, but tried raising others this summer just for fun.
Superworms and dubias... stricty for the beardie.
Waxworms... mostly just to see how it went (produced a ton). Too fatty for a feeder for my beardie, so I fed a few and gave the rest away.
Hornworms... Got hold of some chysalises, so decided to see what emerged. Takes too much space for me to breed, so it was just for fun. They didn't make it.
Black Swallowtail butterflies: Raised 2 of them strictly for fun and release back outdoors into our garden. Fun for my daughter, and will do it again this summer with caterpillars (and hopefully eggs if I can find them). The caterpilalrs eat parsley, so you can raise several caterpillars very cheaply in a Critter Keeper, and just release them when the butterflies emerge.
Monarch butterflies: Found 10 or 15 eggs and raised them to butterflies for release in our garden. Again, fun for my daughter, and we will do them again in the summer of 2009 as well. A bit more work to keep them well fed with fresh milkweed, but the chrysalis is incredibly beautiful, and it is easy to see the entire life cycle.
My daughter is 5 now, but at 3 or 4 had it figured out that the superworm is the beetle equivalent of a caterpillar, the "alien" is the equivalent of a butterfly chrysalis, etc. She realized this on her own while looking at the caterpillars and chysalises in a butterfly conservatory. It was kind of funny to watch a 3 year old discussing this (in pretty considerable detail, for a three year old) with the conservatory staff for close to 20 minutes. Just about everyone there got to hear all about how a superworm "farm" works and how it works just like with butterflies.
So many bugs, so little time...