As a die-hard left-wing anti-British commie-loving ***... I like the queen and the institution of monarchy. If I were setting up a country from scratch there's no way I would have chosen a hereditary monarchy, but in the last century or so it's worked (mostly) rather well and long may it continue. This probably depends, however, on future monarchs following the present queen's example of being utterly apolitical -- as soon as a king or queen starts playing an active role in politics then he or she must be democratically accountable, but if not and the monarch limits themselves to official state functions only then I think we've seen in Her Majesty just how effective it can be to have a fixed point when change is all around.
Congratulations to her for such a long and effective reign.