Honestly, for me, its the message He gives once He leaves the desert that makes me believe in him. The devil tempted Him with the power to rule over all of the world (a temptation to which Muhammad succumbed), but He chose to redeem it instead. Unlike Buddha, He asked people to be active in their world, not try to cut themselves off from it. And unlike those televangelists, He didn't ask for us to send Him money. Instead, His requests are simple: love and give thanks to our creator, love each other as we love ourselves.
I have not found an argument that can refute His laws. I have not found an argument that shows what he asks of us as anything but good. Sure, people have taken His message in many ways that distort it, but His message of love (true love, not the cheap crap we keep being told is love) is undeniable. Seriously, He loves you right now, even with your doubts, even though you think you are unloveable. If you open yourself to it, you can feel His love in this moment, filling you with warmth and light. His love is unconditional, it is constant, and it is right there waiting for you.