I have seen Wicked 5 times so far....going back for #6 in March! My best seats ever were in the center Mezzanine row B, when we sat in row A we all had a hard time seeing over or under the safety railing that runs along the balcony.
A lot of the action in the show takes place up in the air or in the back of the stage, which is why I prefer the mezzanine. We are sitting in the orchestra for the first time in March. We bought our tickets right at the box office in November for March 27 and there were no "good seats" left. We are to the right of the stage, row j or something like that, but we are going with a group of people.
It also depends on when you want to go, Saturdays or any weekend show will be tough......I took my parents in November for their anniversary to a Wed matinee and those were the best seats we have had (bought in May for November)
Broadway.com may have better seats available for only $25 or $50 more than the face value if you can't find seats that you love
I highly recommend listening to the soundtrack and getting to know the music before you go......it is a GREAT show!