There's a note about Marx's ethical ideas at http://www.panix.com/~squigle/vcs/marxethics.html which seems to have been copped from the Encyclopedia Britannica. It seems that Marx (and Engels) whiffed the issue, with a sort half-wave to Hegel; but that may be the writer's prejudice. Otherwise Marx's ethics seem to be emotional and intuitive, like most people's.
Searching on the Net for Hegel's ethics, I get the predictably depressing http://www.connect.net/ron/hegel.html:
...
Ethics and Politics
Hegel's social and political views emerge most clearly in his
discussion of morality (Moralitt) and social ethics (Sittlichkeit).
At the level of morality, right and wrong is a matter of
individual conscience. One must, however, move beyond this to
the level of social ethics, for duty, according to Hegel, is
not essentially the product of individual judgment. Individuals
are complete only in the midst of social relationships; thus,
the only context in which duty can truly exist is a social
one. Hegel considered membership in the state one of the
individual's highest duties. Ideally, the state is the
manifestation of the general will, which is the highest
expression of the ethical spirit. Obedience to this general
will is the act of a free and rational individual. Hegel
emerges as a conservative, but he should not be interpreted
as sanctioning totalitarianism, for he also argued that the
abridgment of freedom by any actual state is morally
unacceptable.
I am unable to read more than a page of Hegel at a time, and then I have to recover for a week or two; can someone tell me if he actually argued stone plain dumb contradictions like "[M]embership in the state one of the individual's highest duties. ... [T]he state is the manifestation of the general will, which is the highest expression of the ethical spirit. Obedience to this general will is the act of a free and rational individual.... [But] the abridgment of freedom by any actual state is morally unacceptable"? This kind of doubletalk seems like charlatanry, as Popper says; and I hate to agree with Popper.
Because I like the idea of deriving ethics from will. We all experience will; nobody experiences the greatest good for the greatest number (as such). This prejudices me a lot in favor of the former; it might be "real". Maybe the will escaped from Hegel's traps and can be found somewhere, breathing quickly, perhaps, but alive and well....