Which Xbox 360 Should You Buy?
If you are looking to buy a Microsoft Xbox 360, there are a couple of basic things you should know before you plunk down hundreds of dollars.  This guide will give you an overview of these tidbits and provide a recommendation on what/how to buy:

There are two versions of the Xbox 360, the Core System and the Premium Edition.  The Core System costs $100 less than the Premium Edition, but gives you less and does not have the same capabilities out of the box .  The Premium Edition provides much more value for the cost and includes items even casual gamers would buy to enjoy the Xbox 360.  Here is what is included in the two versions of the system:

Xbox 360 Core System components:
• Xbox 360 console
• Wired controller
• Standard AV cables
• Detachable faceplate
• Xbox Live Silver membership

Xbox 360 Premium Edition components:
• Xbox 360 console
• Wireless controller
• 20GB detachable hard drive
• Wireless Xbox Live headset
• Ethernet cable
• Xbox 360 Media Remote Control (limited time)
• High-definition AV cables
• Detachable faceplate
• Xbox Live Silver membership

The 20 GB hard drive alone is worth $100!  It costs $30 to buy a 64 MB memory card that has less than 1/100 the capacity of the hard drive.  And you'll need lots of memory to be able to do basic things like play old Xbox games, play Xbox Live Arcade games and download demos.  The rest of the bundled items in the Premium Edition add up to another $100 or so and give you the full capability of the Xbox 360 right out of the box.

The only reasons I can think of to buy the Core system are 1) you are extremely tight on budget and want to buy one now or 2) you are buying this as a gift and you want to let the recipient add all the bells and whistles. 

Conclusion
So what does this all mean?  When you consider how much more you get in the Xbox 360 Premium Edition for the extra $100, the choice is clear - the Premium Edition is the only way to go.  And if you can, pick up one of these games as part of a bundle when you are buying your Xbox 360.  I've played most of these and they are pretty incredible:

• Call of Duty 2
• Madden NFL 2006
• Project Gotham Racing 3
• King Kong: The Official Game
• Kameo: Elements of Power