Jewelry, especially gold and diamonds
valuable tools
Leather goods
guns
ammo
rare coins
If you are interested in portability, then I would tell you to stick to rare coins and diamonds. With jewelry, it would be wise to concentrate on diamonds. THe artistic value of the design and non-diamond gemstones can be written off.
The problem is that when things really get desperate, the basics will be what everyone wants and will kill for. Food, clothing, useful tools and weapons, fuel(whether it be gas, diesel, wood, or cow manure), and don't forget that humans will be a valuable commodity too. Sexually desirable young females and combat capable young males will be bartered commodities in the worst of the worst situations. I'm not suggesting that anyone should take part in the trafficking of humans. But we should all be aware of reality. And if any of us happens to be one of those types of humans that are considered valuable commodities, be aware that you may find yourself in a situation where you will be purchasing your freedom with some of your valuable stash, or you could yourself become a valuable possession of someone else.
You may need to bribe someone with valuables to leave your daughter untouched, or bribe some warlord to NOT draft your son into his gang. Or both. Or you may find yourself better off fighting instead of bribing.
Plan for all possibilities.