Stop paying your cable provider money to rent their modem every month, and get your own for cheap!
I used this with Comcast/Xfinity fine. However, you are responsible for verifying that this is compatible with your service. No returns for incompatibility please.
This was my backup modem, so it's barely used (for a month or two).
ZyXEL BRG35503 DOCSIS 3.0 Residential Cable Modem Up To 160 Mbps Down and 120 Mbps Up RJ-45, Gigabit Ethernet DOCSIS 3.0, 2.0 and 1.1, Euro-DOCSIS 3.0
Gigabit Ethernet connectivity
DOCSIS/EuroDOCSIS 3.0 compliant
4x4 channel bonding
CableLabs CW66 certified