Having used various "Get-a-freelancer" sites, I put 99designs well above others. This is the reason for it (rather 2 reasons):
1. Phenomenal site structure, well thought, rich and flexible
2. Phenomenal support (I mostly used chat).
Specifically, I would like to mention:
- immediate access
- friendly and (oh gosh, it has happened in my life!!!) knowledgeable personnel, who have the authority to make decisions and brains to use this authority.
Thank you, 99designs