In fiction, at least, and I love it. Spoilers follow.
Often, in comics, the death and return of a major character is seen as a cheap ploy to raise circulation numbers, but it's not all a bad thing, if you ask me. For example, I think that Jon Snow died at the end of A Dance with Dragons, and that's a shame. My friend's theory is that he's not Ned Stark's kid at all, but the son of Lyanna Stark and Rhaegar Targaryen. This would have been been an awesome story (I get that some people don't think Jon is dead yet, but let's just pretend it's a sure thing), and Jon's death would foreclose it. Would foreclose it, that is, except that death is a reversible thing in the Song of Ice and Fire series. Lady Stark's come back to life, and Beric Dondarrion has apparently died countless times. Both were brought back by Thoros, a priest of R'hllor (damn, I am totally pulling out the nerd card on this one). This means Melisandre can bring back Jon, and we'll still have that story.
So, that was a long-winded way of saying: What is your favorite fictional resurrection, or do you not like them at all?