More freightening, Xenomorph or The Thing (spoilers?)

I'm sitting here watching John Carpenters The Thing which is one of my favorites. But I was wondering would The Thing be able to infect a Xenomorph? So it got me wanting to ask M/TV board: What's more freightening, the Xenomorph or The Thing?

I myself lean towards The Thing. Not because of any obvious reasons, but because of the first time I saw the scene where one of the guys walks out into the snow at night, drops to his knees and howls that almost metallic scream, I have never been more chilled in my life.