Blu-Ray vs HD-DVD
This is a no-brainer for me. By slipping in Blu-Ray in the PS3, Sony has this "race" locked up. All PS fans and technophiles will snap it up like hotcakes which automatically means millions of Blu-Ray players on the market. Say what you will about the PS3, but it will sell millions of units based on its brand name alone.
Sneaky, but ultimately an effective strategy for Sony. With all the big movie studios behind it, it's hard to see how it can play second fiddle to HD-DVD. Like it or not, it looks like Sony has pulled it off this time.