I was thinking of some sort of lava trap, hidden under the guise of gravel, but contained high enough that he can't bucket it quick. When he knocks out the gravel blocking him from getting further into his house the path of the lava is opened, drenching him and lighting anything flammable in his home. Bonus points if you hide TNT blocks under wooden floor blocks.
I don't take revenge on people for stealing from my publicly displayed chests, but I do get pissed when someone goes through the effort of finding my stash of valuables.
I usually plan ahead my revenge, and it usually takes days to actually put it into action. My usual mode of vendetta is to place a landmine (Pressure plate + Sand + TNT under sand) in front of the offender's front door. And for an added bonus I set it up so that lava pours all over his dropped items as well.
I play on an anarchy server. The only guy I trusted, Quifty, helped me build a mob farm in an abandoned base. I gave him a mod rank for our faction, and he had even left his old faction to join mine. Or so I thought. He was the richest guy on the server, yet he wasn't satisfied. Now, this may have been the owner of the abandoned base, but when I woke up today, sll my buckets and iron were missing. As well as my iron armour. What did I do? I covered the entrance to the cave systems under my house (he has his own, hidden in some hill) that the abandoned base was in with sand and water, and set out to find his base. I'll show that *******. I won't go to far, as I don't have sufficient proof that it was Quifty, but I'll find it.