I'll tell you what NOT to use. I bought Weiman leather wipes. Supposedly, just use the disposable wipes (kind of like those Lysol/Clorox antibacterial wipes) on leather and it's fine. I did a quick clean of my black leather seats in my ZHP. They have been pretty neglected, but still clean. Mostly, just haven't been cleaned/conditioned in a while. The Weiman wipes smell good, but I don't believe it helped clean or condition it in any significant way.
2004 Imola Red over Black Leather. 6-MT, Navigation, Cold Weather Pkg (the wife loves them seat warmers!), 3.46 Diff, UUC Short-Shift Kit, Tranny Mounts, CDV Delete and iPod mount.