Hard to tell, because I complicate things when thinking or overthinking them...but really it would depend on some unspoken factors. For example:
are we talking destruction of the planet, or just my own life being over?
are we talking ANY item/object, fictional or impossible included?
are "extra lifes" and/or objects that grant them "against the rules"?
could this item/object be something or someone living?
IF it was just my own life ending, and IF extra lifes and such are allowed, and IF this could be ANY item no matter how impossible...well to me common sense would be to ask for an eternal wish-granter, thus allowing me to use it to grant me another life or extended lifetime...and then I'd also be able to use it to grant other wishes as well, including more lifes...
IF we are talking destruction of the entire planet, I'd simply wish for the planet itself, whole and intact, with everything exactly as it already is! Then everyone including myself could go on living exactly the way things were, as if nothing happened.
If said item/object could be a person, I MIGHT consider wishing for Jessica Alba, seeing as how I've spent the last 19+ years off and on with my wife already, and my kids are for the most part grown...so I might as well die with a smile on my face! or maybe not....
Otherwise, honestly....I'd just live like any other day, knowing that my own pains and troubles are going to be at an end, and try to be happy and calm about it. As for going out with a "bang", well, there's only 24 hours in a day, and since the morning part had been spent sleeping, there's less...and only so much you can possibly do in that time.
Another possibility: I'd ask for an object to show me the truth of all things past and to come. Why? I'd know the truth behind the creation of life, the universe, and everything; I'd know if there is a God and/or an afterlife; I'd know if I was destined for it; I'd know whether or not that afterlife is eternal or if there was anything beyond even that; and if it was all a big sham then there'd be nothing to hope for anyways and at least I'd die knowing the truth about life on other planets, UFO's, ghosts and the supernatural; magic, ESP,et cetera... and if there IS hope, then I'd have nothing to worry about and be able to face my death with a smile, and tell my family exactly what they have to look forward to, because even if the rest of the world didn't believe me, my family would...and then I'd will this object, if possible, to my wife and kids, to be shared with my family and hers, before being "lost" in the street somewhere for some lucky person to find...thus keeping the knowledge going!
(toldya I complicate things, lol!)
