Being one of your German "customers" myself, I would absolutely vote FOR a localization of Sam & Max. While Splashman mentioned Sam's voice in "Hit the Road" being kinda boring (he doesn't sound as cool as the English voice, that's for sure), but generally Hans-Gerd Kilbinger - who by the way also voiced Malcolm Corley in the German version of "Full Throttle", while Sandra Schwittau voiced his Daughter Maureen in that game - did a good job, making his dry comments stand in beautiful contrast to Max's crazy antics. But I'll agree 110% that Sandra Schwittau was an absolute amazing Max. Different, that's right, but great, and a German "Freelance Police" would HAVE to have her as Max.
And just in case you're considering a localization after all, have a look at http://www.toneworx.com/ as these guys have made the most amazing German versions of a lot of games. Or choose who ever fits your budget.