The "best" modem would be one that your Internet Service Provider (ISP) supports since you would want their assistance in the event of an Internet connection problem.
In other words, it would be of little value to buy a modem that some reviewer or user deems as 'best"....only to find out that the modem does not work correctly with the service that your ISP.
Most ISPs will provide you with a modem...or they could recommend a modem that is compatible with their service. That would be the "best" modem to use.
The AirPort Extreme will work with virtually any DSL or cable modem.
Yhanks for info.