Best Windows Media Server?

Whats the best Windows media server around?

Purposes were:

* Wanted to stream videos to my board-mates, but don't want them to simply click-and-drag to copy all my media. (so FTP/File Sharing is out of the question.)

* Easy drag and drop playlist creation (since I cannot click and drag from folder to Windows Media Player 12, since my tons of media are categorized by folder.) [or if it was possible, please tell me, I'm quite having a hard time making categories within WMP12]

* My machine is Windows 7, and my other mates were mostly Windows 7 and PS3 too, I wanted to have compatibility to both as possible, but Windows 7 is priority.

* A media server having efficient use of the memory.

* Plans were Windows Media Server (as server) to Windows Media Player (as client). << but having a hard time making categories/playlist. (since adding files to WMP12 by library just adds them all up.)

* I only need within- LAN as a server, but WAN doesn't hurt.

Thank you to whomever replies to my problem.