Personally, I've never been able to have more than one bottle of liquer, one bottle of vodka and a case of cellared wine at any given time. I asked a friend how he manages to keep his liquor cabinet stocked - his reply, 'Have guests over a lot. They always bring a bottle or two.'. Thanks Kev.
A simple home bar can have:
beer
Scotch
bourbon
sweet and dry vermouth
sherry
brandy
a few liquers
rum
vodka
gin
seltzer
soda (ginger ale, cola)
tonic
fruit juices (oj, cranberry, grapefruit, Clamato)