I use the AKG 712's (I assume you mean 712 and not 715 which do not exist AFAIK) and they are very nice. For gaming I absolutely love mine. The soundstage on them is very absorbing and while personally not a fan of 7.1 surround sound stuff in headphones, the 712's do work very well with them.
HD660S is another option as PapaLazaru mentioned. While I have not used them myself I have heard great things. Another option however could also be Sennheiser HD6XX (Identical to the HD650, infact packaging on this has HD650 stamped in some places on box) and / or HD58x. I own both of these and they are also similarly superb. Would be from Massdrop for latter two, but the HD6XX will set you back around £225 once you pay import charges and Customs.