#1 (tie): Linksys
Cisco Systems isn't happy with just the No. 1 spot -- it also needs to be No. 2. Cisco's Linksys arm, which used to focus on SMB and consumer markets and now is just a consumer brand, was selected as the strongest challenger to, well, Cisco when it comes to VoIP. Linksys offers affordable solutions for smaller deployments, where its parent targets larger enterprises with more sophisticated needs.