I don't think I've ever owned a tire that didn't have slime in it at some point.
It works, it's cheap, it's easy to use.

Oh, there's an alternative to slime or patching a tire...pool noodles!
Cut them to the width of your tire, and stuff them inside until you can't fit any more of them in there, re-seat the bead, and go drive over some nails.
You can use regular pool noodles or you can buy
Once they're in there, you actually don't need air pressure, like a run-flat tire or something.
Works even better with beadlocks.
http://www.polarisriders.com/104-outlaw-how/32996-walmart-balls-another-poor-mans-tire-balls.html
http://www.quadzoneforums.com/forums/showthread.php?t=26823

The expensive version of pool noodles or Walmart balls are....tire balls.
http://www.tireballs.com/