I have some texts in French (containing accented characters such as \"é\"), stored in a MySQL table whose collation is utf8_unicode_ci (both the table and the columns), that
I know you already have an answer. That's great. But strangely none of these answers solved my issue. I'd like to share my answer for the benefit of the others who may encounter the same issues.
I also had the same problems as the OP, with regards to French accents in a multi-lingual application.
But I encountered this issue for the first time when I had to pass (French accented) data as segments in AJAX calls.
Yes, we must have the database set to work with UTF8. But the fact that AJAX calls had query strings (in my case segments, since I'm using CodeIgniter), I had to simply encode the French text.
To do this on the client-side, use the Javascript encodeURI() function with your data.
And to reverse it in PHP, just use urldecode($MyStr) where data was received as parameters.
Hope this helps.