So, Ruby is OK, Perl and PHP have small memory leaks, but Python has a bunch of worrying errors including undefined behaviors and uses after free !
Of course this does not imply anything on how they manage their memory later, but I think that being clean in the simple case shows if you care about it.
Update: A Rafael wrote in the comments, Perl does not free its objects by default when the interpreter is destroyed, and even if I can't test it, running PERL_DESTRUCT_LEVEL=2 valgrind perl -e '' should not show any memory leak (if your perl was built with -DDEBUGGING). As he pointed out, perl even has a Makefile rule to run all the tests under valgrind.
Update 2: as several people pointed out, the "Use of uninitialised value" from Python are expected and harmless. Does someone have an explanation for the read after free ? :)