The debut day of Steam's 2011 Autumn sale include a bunch of ripper deals, including Mass Effect 2 for $5, Portal 2 for $10, Garry's Mod for $2.50, Limbo for $5 and the Oddworld Oddbox for less than $4. More deals will be made available every day through November 27, so keep checking back for new games.

Source: store.steampowered.com...