The latest VOCALOID producer I have been obsessed with is Utata-P, a.k.a. t.Komine. I've been a massive fan of his works ever since January 2008, when he was first starting out.
My favorites include:
Not A Dream, Not A Lie, A Happy Scene Before My Eyes
Hop! Step! Instant Death! A Happiness Dance Death-Trap
There's Supposed to Be a Cheat Code for Happiness
brand as 〈人を〉
The Path to Eternal Happiness, I Found It