I mean, I wish both of them never existed at all, they are truly abysmal.
That being said, of the two, AvP: Requiem wins by a long shot for me.
1. AvPR has Aliens in it (albeit awful designs).
2. AvPR has Practical effects (when you can see them)
3. The predalien reproduction - I quite enjoyed the addition of egg barfing.
3. The hive set looked cool in AvPR (from the little we saw of it)
4. The Predator was like watching an episode of Power Rangers, from the suits to the spacecraft interior looking like a zord.. it was truly awful.
5. pet pred-dog... really?
6. The Predator ending with the suit is just unforgivable
7. I've rewatched AvPR for its campy b-movie value at least 4 times. I'd never rewatch the predator.