Non-Vocaloid stuff that has been recently added to my mylist:
【マリオ】付箋でストップモーションSuper Mario Post-it Brothers.
【東方】Bad Apple!! 歌ってもらった【アレンジ】Awesome arrange of the now-classic brought to you by Yuyoppe of Vocaloid fame. Badass.
【MAD】決戦兵器エヴァンゲリオン:1.11 ~ エヴァ×GONGEvangelion + JAM Project = 神MAD
I have no idea how to tag stuff here, someone do it for me.