Emotes are a great way to express your feelings toward any given situation during a stream. Twitch has so many global emotes and they all mean different things. During Twitch Weekly they listed the top 10 emotes used on Twitch for 2015, if you missed out you can see them below.
Top 10 of 2015:
Kappa
PogChamp
BibleThump
Kreygasm
4Head
KappaRoss
DansGame
MingLee
Keepo
EleGiggle