YouTube removed the link to view your search by view count.
Here’s a trick around it: (from Google)

• Enter your query on the search box.
• Append &search_sort=video_view_count at the end of the url in the address bar.
• Press enter to search again.
• Result will now be sorted by view count.

Example:
Search for assassin’s creed.
URL from the address bar will be:

http://www.youtube.com/results?search_query=assassin%27s

+creed&search_type=

Add the &search_sort=video_view_count at the end.

http://www.youtube.com/results?search_query=assassin%27s

+creed&search_type=&search_sort=video_view_count

Press Enter to view the result.

Enjoy…