I should also point out that my selections for Q and X are largely driven by the very small number of films I've seen for either letter, rather than any great love for either movie. But they're both enjoyable and can stand in for franchises or genres that I do have tremendous affection for.
Overall, I suppose it ends up painting a pretty fair portrait of my general taste in film. Right then, without further ado:
A is for À nos amours
B is for Blade Runner
C is for Chungking Express
D is for The Double Life of Veronique
E is for Eyes Wide Shut
F is for Female Prisoner #701: Scorpion
G is for Godzilla, Mothra, King Ghidorah: Giant Monsters All-Out Attack!
H is for A History of Violence
I is for Iron Rose
J is for Jaws
K is for Kill Bill!
L is for The Long Goodbye
M is for Mulholland Drive
N is for Network
O is for Out of the Past
P is for Pauline at the Beach
Q is for Quantum of Solace
R is for Rear Window
S is for Suspiria
T is for Texas Chainsaw Massacre
U is for The Umbrellas of Cherbourg
V is for Valerie and Her Week of Wonders
W is for The Wizard of Oz
X is for X2: X-Men United
Y is for Your Vice is a Locked Room and Only I Have the Key
Z is for Zombie
Now I know my ABC's, next time won't you play with me...