Do you mean with or without a DSL modem? If you have a DSL modem that gives you an ethernet port, then you could use just about any Cisco router with 2 ethernet interfaces. Cisco also makes some routers with integrated DSL modems. However if you need to do funky things like PPPoE then it might get a little more complicated. Also if you need to be a DHCP client this wasn't supported until IOS 12.2, so you need hardware that will support the latest IOS.