In my opinion The Predators are far deadlier due to their intellect, weaponry and survival instincts.

Anyone that doesn't say aliens hasn't played AvP2 on the PC :P Though in fairness, I only ever seem to get kills with the face huggers...

The Predator, easy.

" Anyone that doesn't say aliens hasn't played AvP2 on the PC :P Though in fairness, I only ever seem to get kills with the face huggers... "

Depends who or what they're up against and in what numbers. One crafty soldier beat one Predator by outsmarting it but a team of trained marines got massacred by a team of Aliens for being underprepared.

predators are more badass therefore they win

A high ranked Predator could kill a  Queen.

Predators will win eventually, technology is in their favor.

As much as I love the Aliens, dood...the Predators skin motherfuckers alive and hang them from trees.  We know who wins this fucking fight.

Hand to hand, the aliens would win but since the predators are never so stupid to face them that way....predators FTW.

Every Predator or vs film ends with a dead Predator. There's fucking millions of aliens still alive once any Alien flim's credits roll. Can't beat shear unrelenting hoards.