According to this ESPN article the Lakers have the best +/- with less than five minutes remaining in the fourth quarter or overtime with neither team ahead by more than five points.
The Lakers have by far the best Crunch Time +/- this season (+79, the Pacers are second at +65). Pau Gasol (+78) has been their biggest star, followed closely by Andrew Bynum (+74). Kobe Bryant ranks third at +58.
I've never put much into the +/- stat but found this interesting. Our team defense is probably a big help in this category plus the fact that are guys are familiar with each other and don't panic down the stretch.