I have FIOS and love it. Very fast and seems to be more reliable than TWC with regard to internet outages and the frequency at which you need to reset the modem.
2 very notable caveats:
1. Do not fool yourself for one second by thinking Verizon customer service will somehow be better than any one else. Hell mostly likely has a less painful and bureaucratic method of treating child molesters who tortured animals while on their way to rob the elderly. Consider yourself warned.
2. If you use are an Xbox Live subscriber (or plan to be one) and and would like to connect your Xbox to your home network wirelessly, you may have a problem. The standard issue mode/router they supply (Actiontec MI424WR) has firmware that causes NAT issues. Long story short, you may have to hardwire the 360 to your router. No a major issue for some people, but depending on where your console is in relation to your router it could be a pain.