[Every other week, Gamasutra examines the fastest-growing Facebook games according to monthly active users, looking at which titles and developers are having the most success attracting new players on the social network.] In our first look at the fastest-growing Facebook games in the new year, Words With Friends is the biggest "gainer" after picking up around 1 million users in the past week. It now has 16.6 million monthly active users total. Though it's a Zynga title, the game was originally developed by Newtoy, which was acquired by the social game giant (reportedly a $53.3 million deal) last July. The Austin-based developer has since been renamed Zynga With Friends. Tetris Online's Tetris Battle is #2 with 600,000 new users (10.9 million total), followed by King.com's Bubble Witch Saga (10.9 million total) and Zynga's Texas HoldEm Poker (29.5 million total), both of which attracted half a million players. Wooga's Diamond Dash (12.5 million total) and Magic Land (3.6 million) take the #5 and #6 spots respectively after picking up 400,000 new users each. Pool Life Tour added 300,000 new players last week and now has 4 million total. After those, there's a tie between five titles that all welcomed around 200,000 new users, including Electronic Arts/PopCap Games' Bejeweled Blitz (9.2 million total), GSN's multi-game portal Games (5.7 million total), and Playdom's GnomeTown (1.8 million total). Social Point's Men vs Women (1.7 million total) and Halfquest's Arabic game Happy Farm (4.5 million total) also added 200,000 players last week. The full list of the top 20 fastest growing Facebook games along with exact monthly active user counts, are as follows: All charts and data are courtesy of Facebook application metrics and trends site AppData.