Excel 2007 : Retrieving unique values from a list by INDEX,MATCH, COUNTIF

Column B3:B100 contains a list of postcode sectors, which appear more than once. I want to create a list in column C in which each unique postcode in column B appears only once. Previously I have sorted copied and pasted or used a pivot table but am trying to sort column C out with a formula. I have tried to use a INDEX, MATCH, COUNTIF formula (see sample) but it is not working! Am using in cell C4 ( leaving the first cell in the unique list empty) =INDEX($B$3:$B$100,MATCH(0,COUNTIF($C$3:C3,$B$3:$B$100),0)) but am returning #N/A. which should appear when the list of unique values has completed in Column C.
Could someone please help or offer an alternative formula.

Here is also another solution (non-array):

Hi Fortis, my first attempt, thanks for your response and solution.
Mikey

Thanks for quick response and showing both solutions,
Rgds
Mikey