Just out of curiosity (not as if I wanted to run a game like this these days): Are there any good alternatives to Vampire: The Requiem/Masquerade that (instead of just making them available optionally, as Kult does, for example) focus on playing modern day vampires in a contemporary, occultish setting? (Please let's avoid D20-based games. Thank you.)
Good alternatives? I don't know what you think is good! Try these:
There are games that you could use to play vampires that aren't specifically vampire games. Try Sorcerer, for example.
I also think that My Life with Master would be a fantastic game for playing vampires. You'd have a Master who gave you orders and you could all be minion vampires doing awful things. You could struggle to keep your humanity as you did more and more terrible things.
Vincent Baker's Hungry, Desperate and Alone focusses on playing modern day vampires in a contemporary setting. It's a short game, just a blog post.
I don't know whether it's good. I imagine, given that it hasn't been formally released, that it's only half-baked: an interesting game, rather than a polished one.
At the least, though, it's packed with ideas you can use in other games.
Annalise by Nathan Paoletta is a really interesting and playable take of vampires. Not a perfect fit for your specific need but a great game.
Your question sparked a vague memory, and I went off looking for what I seemed to recall. I didn't find it, but I found two other things that might be of interest. I can't actually recommend any of them, as I haven't played them, so bear that in mind.
Death's Shadow: The Book of Vampires "combines the vampire mythos with the unique multiverse view of Karma system to bring Storytellers everything they allow their players to take on the roles of vampires"
Nameless Streets is a Heroquest-based game that includes the option of vampire PCs. It appears to be a sort of modern-day paranormal noir, if that makes any sense. Probably not focused enough on vampires to be useful.
Sorry just a link, because i have never played nor heard much of this RPG.