I guess it would depend on what you fish for mostly but for me,its an 8wt.
More than what you fish for, you want a rod that will throw the size flys you plan on using.
A 8wt is fine in many situations, but a 9wt will let you use larger flys.
The wind is a factor in many areas also.
My "5wt" is a 9...sometimes I go down to an 8, more often I use a 10

------------------
"The day after tomorrow is the third day of the rest of your life"