My gosh Caseydm, you have an enormous yard. Where I live in California our lots are so small that I can practically reach over my side yard fence and tap my neighbor on the head when she's watching tv (I'd like to ... dear God the new neighbors are noisy ... that woman is yelling at someone from dawn til dusk).
We're deciding on what to do for privacy as well. We have 6' redwood fencing all around the back yard, but as it shrinks (we've had it 2 years) there are enough gaps that the privacy is somewhat minimal. In my property in southern California (rental) I have fence & green privacy (plants & trees), and I have to say I really like that option. The greenery doesn't require me to paint it, replace boards, etc. and its far nicer to look at than fence boards, and its good for the air & the environment. However, if you are fencing in for a safety option, or to keep critters out, then that's a different matter entirely.
(and I overheard my husband say to a friend yesterday regarding our pending remodel, "my wife outranks me in the decision department." I never knew that.. good information... laugh)