i'd prefer a combo, actually.
i don't think a president should be limited to two terms. however i do think a president should not be allowed to run in consecutive terms.
during the fourth year, the president spends (wastes) so much time defending his own policies, campaigning, making new promises, etc ... all of which should be time spent being president.
by disallowing consecutive terms, you can ensure that you'll get four solid years of presidenting. and, if that president is especially good and, thus, popular, you can revote him into office every other term, forever.
