Check out Richard Lewis' report on CS:GO gambling sites. Remember: There is no such thing as a "legit" gambling site in Steam; they're violating the Steam Subscriber Agreement to begin with.
Login via Steam

Donators

Donator - Tier V
159 donators
Donator - Tier II
107 donators
Donator - Tier I
145 donators
Donator (Legacy)
121 donators

Valve and Steam are registered trademarks of Valve Corporation.
SteamRep is hosted by the non-profit Online Fraud Prevention Foundation and is not affiliated with Valve in any way.