Silicon Valley, where I live and work, is the obvious answer as to where to find the most innovative security products. Money flows up and down Sand Hill Road, showcase offices spring off of University, startups gather on either side of the 101 from San Jose to San Francisco, and deals are being made daily at coffee shops like Philz, RedRock, and Coupa (where a latte costs .007 bitcoin!).
When I started my innovative IPv6 company 10 years ago, I chose the DC area, as it had the one thing that Silicon Valley was missing back then—customers. Since I was there, great new incubators have taken off, like 1776 and Mach37, and there is strong governmental support for security startups across the region, as well as the remains of the AOL zillionaires to fund.