Always Cisco!
I am amazed people I meet always have Cisco as their first idea when thinking about network equipement.What else then?
Well,... at least I know Lannerinc making network appliance running Intel or AMD chipsets, standard RAM sticks, standard IDE or SATA drives, standard...I have installed dozen of them as routers, with standard Debian. It works quite well, and we also charged them with "tc" to manage bandwidth limitation, "iptables" to track and drop nasty traffic, "dhcp" to serve clients, and an MTA to relay and filter mail.