Zombi 3 - or Zombie Flesh Eaters 2 - and Emanuelle and Francoise are correct. One remaining, #2 in the original set.
This may be a cheat, but #5 has so many clues in terms of text that it is easy to find. Or should I say 'they are easy to find'. I'm guessing it's a double feature of Tomb of Torture and Cave of the Living Dead? Seriously, the art for Tomb of Torture was so fascinating that I couldn't wait for someone else to identify it.
I would say any information visually present is fair game. That's the point right? I've done searches on combinations of actors I knew or unique content to confirm movies I'd not seen but knew I could easily deduce. Paff once read Japanese text from a sheet of paper in one of mine, did a name search, and came up with the movie. Technically I put up a screenshot with the name of the lead character so that's "on me." All that's up for grabs is internet points after all.
Kim your answer is correct. These are the remaining two. The first picture is a Thai poster for a 70's vampire film. The second is an Italian poster for a 60's UK film.