I miss Vanilla Coke.
Vanilla Coke is totally still in production. Sadly the vastly superior Pepsi Vanilla is not.
I also miss Pepsi Twist/Coke with Lemon. So with the absence of those I'd have to say Orange is my favourite followed by Vanilla Coke.
EDIT: nevermind i see that you're in Canada where it is not sold. Bummer.