I'd say that Cliffhangers done well, are addicting. Done clumsily, it's annoying and forced. A cliff hanger needs to pay for itself in some way plot-wise. By that I mean if it leads to something that is just mostly ignored in the following episode, it's irritating.

Finally, I want a reasonable outcome not deux ex machina solution and I want a reasonable curiosity and question asking by all concerned. I mean, if I'm dying of curiosity, the characters should be too.