I would blow on someone and make him fall over like Benny Hinn does to people.
Easy to fake that (by paying the dude you blow on, or getting your bodyguards to convince him to fall down). I don't know how one would go about walking on water - that's a real miracle!
You finally meet the love of your life. But she (or he) is a princess (or prince), and you are very poor. But then her (or his) dad (or mom) says "Go and kill 100 Philistines, and bring me the proof that you killed them, and I will give her [or him] to you to marry!" Would you rather kill 100 Philistines to marry the girl (or guy) - like King David, or would you try to find some other way to get her (or him) to fall in love with you (e.g. by going on a date, or something)?