I guess font support is what matters, not OS, so I combined all the horizontal ones regardless of whether they work everywhere. Paste at your own risk!
- https://en.wikipedia.org/wiki/Kaomoji (顔文字)
- http://unicodeemoticons.com/howto.htm (done)
- http://www.unicode.org/charts/ (look for emoticons)
- everything in the gist comments