Truthfully, I don't think it's necessarily the router. I have a fiber connection with a bunch of computers that are sometimes very active on this network, it's all running off an inexpensive ZyXEL NBG-415N wireless router with no issues. Just changing the router to most any other decent model may solve the issue.
Some things you can try here.
- For wireless connections, change the channel on the router, I like channels 1, 6, and 11 in the US.
- Update the firmware to the latest version available on the manufacturer's site.
- Reset the router to factory defaults and reconfigure.
Many times these measures will resolve a lot of intermittent issues.