How far do you go?

So now that the holidays are over and life has calmed down a bit I have finally found some time to work on my genealogy research again.  This has brought up it's own set of problems and questions.  How far do you go?  I'm currently working on the Meeks family tree, my maternal grandfather.  Of course you always want to trace your ancestry as far back as possible, but how far sideways & forward do you go?  For example, my family tree on Ancestry has exploded with hints for the descendants of my great-great grandfather's sister.  My great-great grandfather only had 2 siblings, a younger brother and a younger sister, only one of whom had children.  But it still begs the question, how far do you go?  Do you trace her lineage down as far as you can, or do you just include her, her children, and her grandchildren?

Part of me wants to stop at her children, so I don't add any more to my already full genealogical plate.  The other part of me, the part that needs to join Genealogists Anonymous, just wants to know everything out there that I can possibly get my fingers on.  I feel like the further down I trace her lineage the better chance I have of going back.  Tracing her life down to her grand-kids might actually give me the ability to find out some really cool stuff.  Or at the very least maybe uncover some family photos.

So that my friends, is the question of the night on my genealogical quest.  How far do you go?  How far have you all taken your family trees?  Do you think you shouldn't have gone as far as you did, or do you wish you had gone further?