Through Windows Live ID you can access your Xbox game account, mails, messages, photos, media, documents, and much more using one single Windows Live account and its password. But what if you have more than one Windows Live account? You might want to use all the accounts for mailing purposes but how to decide which account you should be using for communicating and connecting with other resources which can be accessed by Windows Live, and on what basis?
A Windows Live ID is an Email ID which can be used to sign in to Xbox Live, Hotmail, Zune, MSN, Messenger, SkyDrive, & Find My Phone. This one single ID can give you access to all these resources, if you were using multiple IDs to access these different portals then you can stop doing it that ways and just use one single ID for all. Your selection of configuring the best ID amongst the few available on your Windows Phone would depend upon your work practice. If you use the ID which you use for accessing your Xbox Live account then all your GamerTag information will get configured on your Phone along with your GamerTag Avatar and the Scores. You can use this ID to play your Xbox Live games on your phone. So if you give priority to gaming then you can configure this ID on your Windows Phone.
Other consideration should be for Hotmail. If you have hundreds of contacts in any of your email ID and you use your phone primarily for Emailing and Messaging purpose then it would be good if you configure this Email ID on your Windows Phone. With this you can also go ahead and share your photos on the web using it via Windows Live Photo Gallery and can also stay in touch with friends of your contact list using the Live Messenger.
Last but not the least the consideration should be given to the Zune. It’s being given last place because the MP3s which you have in your Zune Player under some other account will still work even if you use any other ID, but yes if you have lots of Zune friends then off course you can go with the configuration of this ID on your phone so that you can stay in touch with them.
In terms of best practice, Preference should be given to the Email usage of Windows Live ID because all the other things like Zune and Xbox can be reset with your Email ID but sending a new Email address to all your contacts would not be a good idea.