I like ghanns or joshsfrogs/rainbowmealworms if I'm getting other things included. Ghanns shipping can be pricey, but they're the healthiest crickets I've come across.
I buy my feeders from dubiaroaches.com but they are always out of crickets. Honestly, if I buy crickets (which I rarely do) I get them from my nearest pet store and gut load them myself.
I've been going through Ghanns solely for the past year. There has only been issues of supply for me twice with them, I used Flukers to hold me over but that was a bust due to short-shipping. I can't afford a short shipment when I have 50+ hungry mouths to feed. I just do my best to do a weekly / bi-weekly order with Ghanns and generally over order by enough to hold me over for at least a few days.
I'm using a local pet store. Their prices aren't the best, but shipping costs, losses even things out, and with immediate weekly availability, it's the best option for me right now.