That's a very good question, and one which will take a while to list - But here I go!
There are many categories in ebay and naturally each one is popular and each one has it's best selling items or brands.  It would be nearly impossible for a mere mortal to get this information for himself - So what we have done here is collect it from a computer-ma-bob!  Simples!

The information supplied here is collected from the search requests that ebay get - Therefore they represent the items people are looking for the most - At least it allows you to configure your auction title with some really juicy keywords! (I DO NOT advocate using irrelavant keywords in your title or auction).

Thanks for your time, I hope I've been helpful!

SuperCooper

Right...  The categories and best sellers are as follows:-

COLLECTABLES

 1. Star Wars 
   2. Christmas 
   3. Precious Moments 
   4. Swarovski 
   5. Harry Potter 
    6. Christmas tree 
   7. Disney 
   8. Coca Cola 
   9. figurines 
  10. Santa 

    Entertainment Memorabilia Top Keywords
   1. Beatles 
   2. Kiss 
   3. posters 
   4. Star Wars 
   5. Elvis 
   6. Harry Potter 
   7. Marilyn Monroe 
   8. prop 
   9. Rolling Stones 
  10. Metallica