It really depends on what you will be doing in the future: if it will be just a few bolt ons or will you be thinking about power adders/engine builds.
There has been some talk in that you won't see much performance gains by changing 1 set up; 2 gear sets are recommended for experiencing some performance. I went from 3.08 to 3.73 even though I wanted 3.55's because the shop owner talked me into it. I lost about 1-2 MPG in around-the-town driving but picked up some acceleration gains. Changed out the suspension later on for additional performance judged from the butt-in-seat meter.
I am thinking off going to 3.73 but like its said above its noticeable going up two gears thus making me go to 3.90 I do take long trips in my car so I'm sure I'll go with the 3.73