They are all fine; I have used several brands, most recently Trader Joe's. They last a very long time refrigerated, as do tubes of anchovy paste and pesto.
However, if you do open a small can of paste and don't use it all, I suggest you make a few small squares of aluminum foil, place one tablespoon of paste in each one, wrap the foil around the paste and freeze them individually. Then you just take one or two out of the freezer as needed.