"Thumbs up" ping

Aside from communicating game events like roaming or MIA, the whole emote system is used primarily for taunting opponents. In the interest of promoting team synergy, Riot should include a ping to encourage teammates. A simple "thumbs up" icon can show your teammates that you can see they're doing good work. It's a simple replacement for "gj" in chat that could go a long way to promoting friendly player behaviour.

I like the idea of a "warded" ping since the caution/danger ping has so much overlap too, but it seems as though player communication is slanted towards taunting opponents much more than it is for encouraging your own team.