skribbl - Word guessing based on drawing.
Drawasaurus - Drawasaurus is an online drawing & guessing game you can play with friends or strangers.
gartic.io - Draw, guess, and win!
LetsDraw.It - Guess and Draw, Drawing Battle, Pictionary, Copy picture - online drawing games where you can compare your skill with others.
Pictar.io - Pictar.io is a Drawing and Multiplayer Puzzle video game available to play on the Browser.
Sketchful.io - Pictionary type game where each round a different player draws something that the other players have to guess the word for.