The short answer is: you can't. Or at least not with the way things currently work with Gmail. As you've probably noticed, your only options are filtering by a tag or using the archive to hide things. A glance at the [advanced search tools][1] show what you are after isn't really accommodated.

Your question is in a similar vein to those asking how to find unlabeled messages, and a similar answer applies. You can try and build a search that explicitly excludes every other label, e.g.:

    label:inbox -label:{labela labelb labelc}

You can build the search once then save the URL, but given you mention that you have a ton of labels I know it is far from ideal. If you have a look at the [answers][2] to [questions][3] on finding unlabeled messages you'll see you're not alone.


  [1]: http://support.google.com/mail/bin/answer.py?hl=en&answer=7190
  [2]: http://webapps.stackexchange.com/q/275/16377
  [3]: http://superuser.com/q/52441/113679