The Gemara (Pesahim 107a) discusses alternative beverages for wine, known as Hamar Medina, (lit. “wine of the province”), which are considered distinguished enough to replace wine should there be none available. When discussing the cup of wine used for Birkat Hamazon, the Shulhan Aruch (Orah Haim 182:2) rules that Hamar Medina may be used if wine is not readily available in a particular locale, as long as it is not water. This would also apply to Kiddush on Shabbat or a holiday, or for Havdala. The Rama (ibid.) adds that it is therefore acceptable to use beer in the place of wine since it too has some level of importance as a beverage.
Since wine is readily available nowadays, there are those rabbis who say that one may not rely on Hamar Medina for Kiddush and the like. Other counter that since wine is not necessarily a common item in many people’s homes, it could be considered as not being readily available and therefore one may use a non-wine substitute. Rabbi Ben Zion Abba Shaul (Or LeZion, vol. 2, § 20:19) says that the characteristic that renders a drink important enough to be considered Hamar Medina is that it has undergone alcoholic fermentation. Furthermore, the beverage has to be commonly found in that particular locale. As such, beer and Arak, for example, would be appropriate to use as Hamar Medina.
Other drinks have a questionable status regarding Hamar Medina. Rabbi Ben Zion Abba Shaul understood that whiskey was not commonly consumed in Israel, so may not be fit for replacing wine. It appears to be more common in other countries and indeed some Poskim do consider whiskey acceptable. Even so, Arak or whiskey may not be a good idea to use for Kiddush, etc., since one should preferably drink the requisite Revi’it amount, which may be challenging. Some Poskim say that coffee or even freshly squeezed orange juice may be considered Hamar Medina, but these are not clear cut choices. Milk is mostly consumed for health purposes while fruit juices contain mostly water and as such neither are generally regarded as being distinguished enough to be Hamar Medina.
Summary: If one cannot use wine for Kiddush, Havdala or Birkat Hamazon, one should preferably use beer or Arak. All other beverages are questionable.