Word Domination
Lexica
Crosswords Arena
Quackle
Words With Friends
Tanglet
Wordbase
Wordfeud
SketchParty TV
Drawasaurus
LetsDraw.It
gartic.io
skribbl
Cast-a-Draw
iSketch.net
Drawception
Word DominationLexica - An open source word-search game.
Drawasaurus - Drawasaurus is an online drawing & guessing game you can play with friends or strangers.
Crosswords Arena - Word game, multiplayer and computer players
LetsDraw.It - Guess and Draw, Drawing Battle, Pictionary, Copy picture - online drawing games where you can compare your skill with others.
Quackle - Open-source word game similar to Scrabble. Features a board editor, analysis tools, and artificial intelligence that rivals the best players in the world!
gartic.io - Draw, guess, and win!