I'll be in a desert island so much if my diet will be low key and while not lacking flavour won't be big on impact. Likelihood is if it does have a strong taste it'll be a horrible one.
So I've been considering carefully, Scampi Fries are out, much will be tasting of fish anyway though the undercurrent of lemon is tempting. My standard work crisp if Thai Red Chilli is a contender but ultimately lacks punch, as does the secondary backup work crisp of McCoy's Meaty which is in the same boat, though tempting for the filling you up aspect.
Walkers are all to bland even on a daily basis. Skips and Quavers are to light and ephemeral. As are bacon frazzles though nothing like a lingering bacon flavour burp several hours after eating to many.
No for a desert island there's only one choice.