Coffee I suppose. Although I can go without it for several days, I ususally choose not to.
If I have potato chips in the house I end up gorging myself on them.
(so I don't keep any on hand)
Hmm, what else... oh, cheesecake. I once bought one of those mixed sampler wheels, a giant one, about 24 good-sized slices. I finished it off in about 10 days, being the pig that I am.
(I don't keep that on-hand either)
Weakness is the better word. I'm really not the addictive type.