I moved from a regular $50/month landline to Asterisk with voip.ms as line provider ($2/month). The results are really impressive. This is an old video I made, when I was testing the setup. What I like about Cisco phones is how elegant they are and how great the sound quality is with Asterisk.
I run Asterisk on a NUC server (CentOS 6 x86_64, tiny box next to mouse), that also managers my APC Pro and sends me emails when the power is out. It shuts down gracefully the servers when the APC reaches a certain percentage and restarts them back when the power outage is finished.