I use
Reptile Supplies, Reptiles, Amphibians, Invertebrates, Cages, Feeders, and More for crickets, and reptile supplies.
I've used
kingsnake.com - the information portal for reptile and amphibian hobbyists. to find some of the more hard to find herps.
I use
Frozen Mice, Frozen Rats, Rabbits, Guinea Pigs, Chicks and Quail if I need to buy feeder rodents (though I mostly breed my own mice, gerbils, rats, and rabbits)
craigslist: houston classifieds for jobs, apartments, personals, for sale, services, community, and events is your best bet for enclosures, bar none.
Rodentpro is expensive. I won't deny it. But they've got great prices and a huge selection. They do, however, gouge the hell out of you on shipping. ($50/box and it's shipped ground.) If you've got a big collection, and they reliably eat frozen/thawed, I can recommend them.
kingsnake.com is a classifieds site. There are some great breeders on there, and there are some monsters who should be thrown to the gators. Always do your research before buying.
lllreptile has pretty good prices, and reasonable shipping. They have absolutely great cricket prices. 1000 large crickets, over night, for $26. And they don't have that cricket blight either. I get my thermostats, as well as my wood, my filter cartridges, vitamins, calcium, and various cage furnishings from them. They also carry a very large selection of animals, from geckos to anacondas.
Craigslist is absolutely amazing for getting cheap used aquariums. This summer I picked up a 75 gallon with stand and lid ($50), a 55 with stand and a 40 long ($50), as well as over a dozen 10 gallons for under $3 each. You can really find great deals on aquariums on craigslist. You can also find animals on craigslist, but in most cases it's someone wanting to "rehome" an animal for more than the cost of the animal. You'll find it full of $70 bearded dragons, $50 corn snakes, and $80 ball pythons.