There seems to be a genetic component to how we perceive the taste of some of these artificial sweeteners [1]. Personally, I also think stevia is gross -- bitter and metallic aftertaste.

The best AS for me is sucralose (Splenda). I can't tell it apart from sugar. I've also never seen any results about it that would concern me, and it's been studied more than almost anything else we eat.

[1] http://news.psu.edu/story/284556/2013/08/20/research/multipl...