Vodka

Vodka is an European clear distilled alcoholic drink that has been one of the most popular drinks across the world .

You'll find it to be the most popular spirit in drink making because of it's neutral taste and absence of flavour and colour.

Vodka often replaces Gin in many traditional cocktails

Vodka is known to be good for the heart, and if consumed in moderation, can prove to be good for cardiovascular health

Note that these days there are flavoured Vodka available in the market too, and some cocktails do make use of them.

Bacardi

Bacardi 151 is a discontinued brand of highly alcoholic Rum made by Bacardi Limited of Bermuda. It is has alcohol concentration level of 151 US Proof or has 75.5% alcohol by volume. Way higher than a regular 35% - 40% ABV of a standard Rum. Bacardi discontinued the 151 in 2016.

Because of it's high alcohol concentration a 151 Proof Rum is highly inflammable and is thus used in making stunning flaming shots. Bacardi probably discontinued the Bacardi 151 after a few lawsuits, but there are other brands of 151 Proof or overproof Rum available in the market

Bacardi Limon Rum is a Citrus Rum, Bacardi introduced it in 1995 and Bacardi Limon Original Citrus Rum is their first ever flavoured Rum. Bacardi Limon is a blend of Bacardi White Rum infused with a delectable combination of natural lemon, lime and grapefruit, the name Limon is the French for Lemon.

People often confuse it with a flavoured Vodka, but it's pure Rum.

Bacardi O is an orange flavoured Rum, created by infusing Bacardi White Rum with the essence of Mandarin Oranges from Sicily, Valencia Oranges from Florida and Dancy Tangerines from Brazil, Florida and Israel.

Bacardi O is 35% ABV.

Breezer is an alcoholic fruit flavoured beverage made by Bacardi. Breezer comes in a variety of fruit flavours and are available in lemon, peach, apple, pineapple, lime, orange, ruby grapefruit, blackberry, watermelon, cranberry, coconut, raspberry, blueberry, pomegranate, mango and strawberry flavours. Breezer is popular in India, Europe, Israel, Australia and Canada and is available in China too. A Breezer in reality is not a real fruit leverage, it is a wine cooler, which is an alcoholic beverage made from wine and fruit juice, often carbonated beverage and sugar is added to it.

Blue Curacao

Curaçao is a liqueur flavored with the dried peel of the bitter orange laraha. It's been a popular liqueur for more than 150 years, the Dutch East India Company created this orange liqueurs by steeping orange peels in alcohol from the island of Curaçao and called it Curaçao liquor, unlike Triple Sec, Curacao has added spices and herbs to the orange and Curaçao comes in a variety of colours such as clear, orange or blue.

Blue Curaçao being the most used of them, in cocktails. Although Curacao is an orange tinted liquor, Blue Curacao is a regular Curacao dyed bright blue to give it a striking appearance, and thus is a very popular cocktail mixer, whenever a striking colour is desired.

Blue Curacao is usually around 25% ABV.

Blue Curacao is essentially Orange Liqueur tinted Blue, the colour doesn't influence the taste and thus Orange Curacao is interchangeable with Blue Curacao in recipes, if the colour is not important in the appearance.

NOTE: Blue Curacao being an Orange Flavoured Blue Liqueur, it's primary purpose in a cocktail is introducing the Orange flavour and the striking sky blue to the drink, so, if a bottle of Blue Curacao liqueur is something you are not planning to buy right now, you can manage with the Blue Curacao Syrup.
It would add the same flavour and colour profile to the cocktail, all we need to do is simply count for the alcohol absent in the syrup and account for it.

Grand Marnier

Grand Marnier is a French liqueur brand. Their most well known product is Grand MarnierCordon Rouge, an Orange flavoured liqueur created by Alexander Marnier Lapostolle in 1880.
It is made from a blend of Cognac brandy, distilled essence of bitter orange and sugar. It is 40% ABV or 80 proof in USA.

Grand Marnier is a French Brand of liqueurs. The most well-known product is the Grand Marnier Cordon Rouge, an orange flavoured liqueur made from a blend of Cognac, brandy, distilled essence of bitter Orange and sugar. The Cordon Rouge was created in 1880 by Alexander Marnier-Lapostolle. It has 40% ABV.
Grand Mariner is full of rich, complex flavours and intrigues of the Cognac, and makes cocktails taste. A Grand Mariner is a blend of Cognac and Triple Sec, it's not a traditional Curacao, it's a similar orange liqueur.

Apple Juice

Apple juice is a fruit juice made by maceration and pressing of an apple. The extract is usually clarified of suspended starch and pectin and then pasteurised and bottled or further clarified to produce a commercial juice. Apple juice manufacturing being an expensive process, it is mostly produced commercially worldwide.
Apple juice if unconcentrated, is 88% water and helps rehydrating the body, it contains beneficial plant compounds like polyphenols. Lakewood's Organic Apple Juice is one of the best choices of Organic Apple Juice, while Mott's Sensible Apple is the brand that has the least added sugar in it.
Apple juice goes well with Vodka too, while dark liquors like Bourbon and Dark Rum had been the traditional choices with Apple Juice.