-Piano/Classical Music Concert - Something sharp to keep you awake, maybe Blenheim's Bouquet
-Quiet, peaceful night - An ambery oriental
-Dinner in a restaurant - An ambery or edible oriental (I think orientals are best at night)
-Work - A fougere scent, or chypre scent,
-Going to the shopping mall - Nothing, if you're going to try on shirts or jumpers
-Going out with a bunch of friends - Depends on time of day, and what you intend to get up to.
But my favourite all round scent that can be used for just about any purpose is still Boss Elements.