They made a couple of Alien Vs. Predator movies.  I never saw them, but I heard they weren't very good.  What they really need to make is an Alien Vs. Alf movie.

Do you remember Alf?  He was the wise cracking, cat eating alien from the 80's TV show of the same name.  He was stranded on Earth and living in secret with a suburban American family.  Most of the time I'm pretty sure he was a puppet, but I think for some shots they got a little person in a costume to show him running around.  

I thought Alf was great when I was a kid.  I'm not sure how well the show would hold up now.  I remember the most frustrating part was it ended on a cliffhanger.  Alf was trying to connect with his own people who were flying by in a spaceship so he could go home.  The last thing we saw he was surrounded by government agents and To Be Continued... flashed on the screen.  And then the show never came back.  This was immensely disappointing to me and was the beginning of how I learned to mistrust those no-good slimy TV execs.  

Incidentally I recently learned they apparently made a TV movie years later to wrap up Alf's storyline.  I never saw it and I don't remember hearing about it at the time, so "yay" to whoever greenlit the concluding story, but "boo" to the networks for not giving it major promotion.  

But getting back to my initial point, I think an Alien Vs. Alf movie would be awesome, or at the very least awesomely weird.  Sure on paper it seems like the Xenomorphs would eat Alf in one swallow, but he IS from an advanced spacefaring civilization and he seems like a pretty smart guy.  I think if he put his mind to it, he could do some real damage.  If nothing else, I'm sure he'd inflict some verbal damage with his cutting wit.  But, really, I've always wanted to see Alf in actual action.  Come on, Hollywood.  Make it happen!