I love suggesting DDs and today is my 13th success. I do not count failures but I think it is about a 1:3 success/fail ratio. Plus, this is not counting DDs I suggested, were featured, but did not list me as a suggester. I do not always like the picture that are given DDs, and while it is up to the GMs taste, they can be influenced by a suggestion. In fact, I suggest so much that I created a folder in my favorites gallery for works I want to suggest.
My DD Worth Favorited Folder http://coloradogirl86.deviantart.com/favourites/43242510
Here is a list of DDs I suggested, that were accepted.
1. http://first-last-fallen.deviantart.com/art/Lust