I am looking to add value to my 5 year old home and the three areas that are a possibility are: 1. Finish off the already roughed in bathroom in the basement to go from 2 to 3 full bathrooms. 2. Add an unattached 2 car garage 3. Add on to a small walk in closet to make it twice as big?

I would think first would be finishing the 3rd bathroom, and 2nd probably doing the garage, to add value in the most productive way.  These will help you if and when you get an new appraisal done.

Are you looking to sell soon?  If so, you might want to consider how much quicker the property would sell by the selection that you make.  Finishing the bath might give the best return, but having a garage may sell the property faster.

If you are not looking to sell, pick the option that will give you the most enjoyment or utility.