I usually root for either underdogs, or storylines in the NCAA, so I guess I'll root for Duke to win it all in Coach K's last season.
Houston - don't care.
Purdue - it'd be cool if they won
Arkansas - don't care
Kansas/Providence - don't care
Duke - Coach K's last year be cool if they won
UCLA/NC - don't care
Iowa State/Miami - no shot
St Peters - no shot
So of teams that have a reasonable chance to win, i hope Duke or Purdue win it.
But ultimately, this is a very boring set of teams remaining. Maybe Iowa State can pull it off. To go from 2-28 last year to the Final 4 would be something. But other than that its hard to find a compelling underdog team to cheer for.