I ran a private contest for a book cover design, meaning submissions from other designers were not visible to the 99design community. Much to my surprise, the winning design came in during the final days of the contest. Zeljka's (KikaIkaMika) entry rocked all my polls later on - which was great.
I particularly liked that:
a) all my design requirements (or rather thoughts on what might be good examples of what I am looking for) in the brief were considered before submitting
b) Zeljka was open/flexible to "play around" with different options based on my feedback
c) quick turnaround
In short, I'll definitely have Zeljka on my shortlist for future gigs, and recommend anyone looking for similar work do the same.