I use Maya default with a dab of some custom scripts (TransUV, my own UV slot mover, and XFormUV) found on the net and UVAuto Ratio Pro for sizing. Maya's defaults are pretty good, just buried (like everything else).
can't help but notice lots of Max people here (although I love Max myself). I guess it's just the fact that I've been using Maya so much as of late that I will chime in on Maya UV tools I use and that would be the sdv_xformUV script which does plenty of the things I need to do with UV islands or arranging things and such.…