How about seeing only those in your address book? For a shorter list and faster picking, you can set up Windows Live Hotmail to auto-complete only names and addresses in your contact list, not everybody with whom you've exchanged mail in the past.
Have Windows Live Hotmail Auto-Complete Addresses Only for Contacts
To prevent Windows Live Hotmail from suggesting people not in your address book when you address messages:
- Select Options | More options… in Windows Live Hotmail.
- Follow the Advanced privacy settings link under Customizing Hotmail.
- Make sure Only suggest people in my contact list is selected under Auto-complete suggestions.
- Click Save.
(Updated July 2011)