dubias are easy, and all i have experience with. it's simple and there's plenty of instruction on the internet regarding care/breeding..silkworms are harder to breed, so i don't do that. crickets are smelly, labor-intensive, prone to death, and cheap at the pet store, so I don't breed them either. i use dubias and crickets as a staple, and i buy superworms as a treat by the thousand online (cheap, and lasts a LONG time), and i buy silkies/hornworms as treats every once in a while. this seems to be the easiest system for me.