While reading the blog for www.craftzine.com today, they have a post about a list of stores that sell eyes for making amigurumi. Since I've seen several people ask about where to get eyes, I thought I'd share the link.
http://www.planetjune.com/blog/amigurumi-help/eye-sources/ She doesn't review all the stores on the list but she does have shops that are out of the USA (which will be beneficial to our international members). Some of the readers of this lady's blog do review a few of the stores.
Personally, I've only ever used Darice eyes or made eyes from felt. I can say that the Darice safety back eyes are great. :-)
Hope this helps.
Now, I'm off to go work on my amigurumi along project for this month. :-D