ISNULL() has its own oddities:
DECLARE @var1 char(1)
SET @var1 = NULL
SELECT ISNULL(@var1, 'N/A') -- Result = 'N'
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial:
If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them.