For occasional use, get the injection-molded cooler.

Probably the injection-molded one. Rotomolded coolers are built like tanks — they’re rotomolded (hence the name) from a single piece of plastic, so they’re incredibly tough, have thick insulation, and will keep ice for days. They also cost $200–$500 and weigh a ton.

For occasional tailgates, beach trips, or picnics, you don’t need that. A good injection-molded cooler (like a Coleman Xtreme or similar) will hold ice for a solid 24 hours, costs $50–$100, and won’t break your back carrying it to the car. The only real downside is they’re less durable — drop one off the tailgate and it might crack. But for occasional use, that risk is low.

If you’re camping for a week off-grid or guiding river trips, sure, get the rotomolded one. Otherwise, save your money and buy a nice six-pack instead.