I’m personally of the opinion that revenge is morally dubious as all hell; but it undeniably makes a great story engine for a piece of fiction. It gives your character a large and important (and possibly dangerous) goal to work toward; it implies an interesting backstory of some variety; it insures that your character is either going to have to get off his duff and do something or at the very least spend some interesting screen time justifying the fact that he isn’t; and it provides lots of hooks on which to hang moral and ethical and social debate if you go in for that sort of thing.
As plot devices go, you can’t beat it with a stick.
Dr. Doyle's Blog 
The most interesting conflict for a character is almost usually a conflict of moral nature, so what better way to explore that side of him/her than with revenge? It’s morally reprehensible, but at times one can be fooled into thinking it’s also morally responsible.
You could make a long list of literary works that use revenge as a plot engine, without even having to leave the Western canon — Hamlet, Moby-Dick, Njal’s Saga, The Count of Monte Cristo, the list goes on and on.