Well, not sure if these are hardstyle strictly speaking, but all are must haves for me personally:
atmosphere records uk1 (creatures)
atmosphere records uk2 (am frequencies rocks)
lengo - life in x
everything on stigma (especially house of house)
the mdma e.p (force 9 & fj project rmx)
louks new label compulzion (in fact everything by louk)
cally n juice - you dont know me
everything on intolerance recordings
anything by montorsi in the last 12 months, and luca antollini

I could go on all day literally ;)