I think in order to answer this question you would need a minimum of 50 games played on each title to make an educated decision. If we are going off looks and game play video I would have to lean towards Houdini. My concern with Alien is that I will like it but will not love it. I played Full Throttle and it is a fun game but not a game I would want to own. I do not care for the LCD screen on the playfield and I feel it is a distraction(honestly I hope the lcd on playfield idea go's away). I really like Aliens as a theme so that would really help with wanting to own one if the gameplay blows me away. Houdini on the other hand looks like a classic Williams game, and the theme is also awesome. I love having choices and both are great games but if I had to go in blind today without playing either one I would get a Houdini.