I was just playing Red again for the heck of it, and this discussion topic came to mind. Since all of your stuff is in a single bag in this generation, you have to decide how to sort things so you can find anything...what does your inventory look like near the end of the game?

My preferred order:

Itemfinder
Bicycle
Super Rod
Items that restore HP, from least to most effective
Antidotes
Parlyz Heals
Awakenings/Poké Flute
Burn Heals
Ice Heals
Full Heals
Full Restores
Ethers
Max Ethers
Elixers
Max Elixers
Revives
Max Revives
Poké Balls, from least to most effective
Anything else pretty much just randomly ordered.