I hesitate to put Felix Mendelssohn in this list, because he was a Christian all his life. Jews claim him because his grandfather Moses Mendelssohn was a famous Jewish advocate of a certain type of assimilation -- but a believer and an observant Jew all the same.
I don't want to make this into a list of people who can somehow someway be claimed as Jews; my motive isn't to prove something about Jewishness. Mendelssohn was such a great composer I'm tempted to include him anyway, though it's a stretch to call him any kind of Jew other than racial.
In fact, looking over my list of heroic people -- that is, the ones whose values seem to me to support a positive secular Jewish point of view -- I realize that I'm often in opposition to the Jewish listers who are obsessed simply with who was Jewish or had Jewish ancestors. I value as a major positive characteristic that a person would have taken away a certain moral and ethical philosophy while rejecting, ignoring, or neglecting Jewish practice and belief. I hold this up as a virtue: a secular Jewish virtue. I also do not have anything against the practice of Jewish ritual, but I do not regret when someone decides not to.
Maybe my overall listing looks chaotic, but this is what I think is behind it.