A rather nice situation—yet still perplexing—is to receive an "early offer" from one of the companies with which you have interviewed. By "early," I mean in relation to other potential job offers. You may have had eight interviews in the last month, three of which resulted in second interviews, but one of which resulted in an immediate offer. Worse things can happen.
Yet it still creates a dilemma. Sure, if the offering company is your first choice, accept the job and send the others your regrets. But if not, then what?