Some of my favorite movies (that haven't already been mentioned):
Below Her Mouth (real oral, although not explicit, and Natalie is gorgeous)
Erotica Luz de Luna
All About Anna
Now and Later
I also love it when a legitimate or "mainstream" actress goes extremely far for a role. Some of my favorite examples that involve multiple nude and sex scenes, in some cases explicit:
Elisabetta Cavalotti in Guardami
Chantal Demming in Caged
Maria Bopp in Me Chama de Bruna (nothing explicit)
And then gorgeous actresses in graphic scenes:
Eva Green in the Dreamers
Eva De Dominici in Tiger, Blood in the Mouth
Anna Maria Sieklucka in 365 DNI and the sequel
Carole_Brana A l'aventure
Michelle Borth - Tell Me You Love Me
Letícia Colin in Bonitinha, Mas Ordinária