We went to The Columbia Room for Jon's birthday, wherein Audrey had and enjoyed a White Lady cocktail. We've begun researching and working on our own version. Wikipedia has an unusually detailed article on it:

2 parts gin (Plymouth or other medium-body gin, not a super-botanical one)
1+ part lemon juice
1 part Cointreau
Optionally, egg white - from 1 tsp to a half of an egg's white

Sugar the rim of a wine or martini glass (champagne coupe if using egg)

The sidecar is nice, citrusy drink with brandy as its base spirit. Modern mixtures often have equal parts, I prefer a 3/2/1 mix:

3 parts Cognac
2 parts lemon juice
1 part Cointreau or triple sec

Mix the ingredients in a shaker half full of ice. Strain and serve with crushed ice in a sugar-rimmed lowball. Garnish with a strip of lemon rind.

Note that the original mixture, according to The Fine Art of Mixing Drinks, is:

8 parts Cognac or Armagnac
2 parts lemon juice
1 part Cointreau or triple sec

Brazil's national cocktail.

2 oz cachaça
Juice of one lime
½ lime cut into 4 wedges (or tahiti lime, but not key lime)
2 teaspoons crystal of raw sugar

Place lime slices and sugar into old fashioned (low tumbler) glass and muddle. Fill the glass with crushed ice and add the Cachaça. Top with soda.