A link state routing protocol is best suited for medium to large-sized networks as it provides quick convergence due to each router having a complete picture of the network's topology. Link state protocols, like OSPF, use shortest path first algorithms and send updates only when there are changes, making them more scalable and efficient than distance vector protocols. Distance vector protocols, like RIP, are simpler and suitable for smaller networks; they periodically send the entire routing table, which can cause slower convergence and more bandwidth usage. Hybrid protocols, like EIGRP, combine features of both but are proprietary to Cisco.