i have comcast as an Isp could you tell me what is the best modem to buy for comcst service and gaming xbox live
Comcast should be able to answer that question if you give them a call. I'm sure they sell / lease modems for their services.
What service level do you have? I'm not sure if Comcast does phone services, but if you are only getting internet from them, I'd recommend this modem for gaming. I use it myself and it is very reliable.