Best router is not some prebuilt POJ with some naf old style cpu that is antique, you will end up with trouble at some point in its life, and they have huge restrictions on functionality, like dont forward more than 1000 ports total, you will crash it.
My router = a pile of old PC bits thrown together,
gigabyte mobo/ 1.4 AMD TB (Thunderbird) 512MB ram, some old 30GB hdd. 1 x 10/100 nic and 1x 10/100/1000 nic. Throw on a linux distro, this is free aswell
I use suse, theres a large choice of free firewalls that you can install that will fluently handle IP forwarding, My favourite is Shorewall. You can go lower in spec, it just depends on what you have kicking about. if you really must have wireless now you can choose between any ethernet AP to plug into your switch. If any component dies its not a router in the bin just replace whichever component has gone faulty. Not only can you repair it with ease the system is very future proof aswell. Its kind of like buying a all in one AV system inc speakers when theres much better available, but this time it can prove to be cheeper and way superior than a prebuilt unit. I mean you could practically build this from new today for about the same price as a hi end respectable domestic cisco router. It will fully support NEt snmp for complete network and hardware monitoring including all systems connected.
My current uptime for the router
# uptime
5:23pm up 90 days 22:15, 5 users, load average: 0.00, 0.00, 0.00