Left-to-right, top-to-bottom, everyone I think I know.

Row 1

1. Pulp Fiction
2. No idea
3. No idea
4. No idea
5. No idea
6. Mario brothers
7. No idea
8. No idea

Row 2

1. Joker, Batman and Two-face?
2. Simpsons
3. Sonic?
4. TMNT
5. Che?
6. No idea
7. No idea
8. No idea
9. No idea

Row 3

1. No idea
2. Terminator
3. Dracula?
4. Frankenstein
5. Mummy
6. No idea
7. Beatles?
8. I know this one! There's even an online flash game where you can fight as the characters. I can't remember the name. Some cartoon show. EDIT: I remembered! It's Teen Titans!
9. No idea
10. No idea

Row 4

1. No idea
2. Spock
3. Charlie Chaplin
4. Spider-man
5. No idea
6. No idea
7. Link?
8. Matrix (Trinity, Neo, Morpheus)
9. Star Wars baddies (Emperor, Darth Maul, Boba Fett, and I don't know the last one)
10. Tron
11. No idea
12. No idea

Row 5

1. Star Wars (Vader, Kenobi, Yoda, R2D2, C3PO)
2. No idea
3. Asterix (and Obelix)
4. LOTR (Frodo, Sam, Merry, Pippin, Gimli, Legolas, Aragorn, Gandalf)
5. Pirates (Jack Sparrow, Elizabeth, Will, Barbarossa)

Row 6

1. A-Team
2. Benny and Joon?
3. Kickass
4. True Grit
5. Scream
6. Finding Nemo
7. Angry Birds?
8. WB (Bugs, Daffy, Elmer Fudd, and Yosemite Sam)
9. Hello Kitty

Row 7

1. Jason
2. Watchmen (I don't know all their names)
3. Toy Story (Woody, Buzz, Potato-head, pig?, and the aliens)
4. Zorro?
5. No idea
6. Looks vaguely familiar (I think jeff daniels is one of the characters in this movie)
7. No idea

Row 8

1. Shrek and Donkey
2. No idea
3. Flash?
4. Pac-Man
5. No idea
6. No idea
7. Gorillaz, maybe?
8. No idea
9. No idea
10. No idea
11. No idea
12. No idea
13. No idea

Row 9

1. No idea
2. Southpark (Don't know which one is which)
3. Hellboy and that fish creature with the british accent
4. Mr invisible?
5. No idea
6. No idea
7. No idea
8. Calvin and Hobbes!
9. No idea
10. No idea
11. Wizard of Oz (Dorothy, Tinman, Lion, and Strawman)
12. Megaman

Row 10

1. No idea
2. Men in Black?
3. Green Hornet?
4. Marvin from Hitchhiker's Guide to the Galaxy
5. No idea
6. No idea
7. Velma, Fred, Daphne, Scooby, and Shaggy
8. No idea
9. Martian from Mars Attacks?
10. Addams Family?

Row 11

1. No idea
2. No idea
3. No idea
4. Neytiri and Zhake Soo-li (from Avatar)
5. The thing from Nightmare before Christmas
6. KISS
7. Pikachu and Ash (from Pokemon)
8. No idea
9. No idea
10. No idea
11. Jay and Silent Bob?
12. Wonder Woman?

Row 12

1. Smurf
2. Harry Potter, Ron, and Hermoine
3. No idea
4. No idea
5. No idea
6. No idea
7. No idea
8. No idea
9. No idea
10. Waldo
11. Sulley and Mike (from Monster's Inc)
12. Gru, kids, and minion (from Despicable Me)

Row 13

1. No idea
2. Big Lebowski (Dude, and John Goodman's character)
3. No idea
4. Michael Jackson?
5. Mickey Mouse?
6. Futurama (don't know their names)
7. No idea
8. No idea
9. Rush Hour
10. No idea

Row 14

1. No idea
2. V
3. Robocop
4. No idea
5. No idea
6. Tweety and Sylvester
7. Dixie Chicks?
8. No idea
9. Pepper from Dodgeball
10. Incredibles (Dash, Vi, Bob, Helen, Jack-jack, and Syndrome)

Row 15

1. No idea
2. No idea
3. No idea
4. Avatar
5. No idea
6. Lethal Weapon? (Riggs and Murtaugh)
7. Ice Age (Sid, Manny, Deigo, and the baby)
8. No idea
9. Teletubbies (Tinky Winky, Dipsy, La-La, Po)
10. No idea
11. No idea

TL;DR: I don't know many of them

EDIT: I have counted and I either know or somewhat know 202/315 faces