UPDATE (AGAIN): It looks as if Amazon.com in the US is also providing a couple of collections for digital PC download for sale on Sega games. However only one of the packages activate on Steam. That being the Dreamcast Pack containing Dreamcast Collection Volume 1 (Which contains Sonic Adventure DX, Crazy Taxi, Space Channel 5 Part 2 and Sega Bass Fishing) and Jet Set Radio for $4.99. The Genesis pack is still on sale for $4.99 as well, however those do not activate on Steam, but that’s still 50 Genesis games that also sell for $7.50 a pack currently.
While this is not really a deal, they also sell Billy Hatcher and the Giant Egg for digital download PC. (This also does NOT activate on Steam) Still noteworthy.
UPDATE (12/3/2012): Sonic Generations is 75% off again on Steam until December 10th as part of a sale celebrating the official release of Big Picture Mode. Another Sega game, Hell Yeah! is 75% off as well. You can check out all of the other deals here. Amazon is also having a sale on downloadable Sega games, with various bundles. This includes the Sonic Action Pack for $25, which includes every downloadable Sonic game besides Sonic Adventure 2. These deals are good until December 8th and can be seen here in this NeoGAF thread.
Those who have used Steam for at least half a year know that their sales are usually pretty darn good, with lots of games usually being 50% or 75% off. Like now Sonic Generations is 75% off until November 27th, which is a great deal if you don’t have the game yet. All other Sega games on the service besides those that came out during the last month or so are 50% off as well. Other good games on sale are Dishonored for 50% off, Batman: Arkham City GOTY Edition for 75% off and Deus Ex: Human Revolution for 75% off.
Also, if you missed out on the Starbucks deal for Sonic 4: Episode II you can get Episode I for $2.99 and Episode II for $3.74 on Amazon. Both episodes use Steamworks so you’ll have to activate them on Steam in order to play them. The Sega Genesis Classic Game Pack is also priced off to $4.99 and includes 50 Genesis games.