If you just want to game the i5 6600k is fine, games wont run much faster with the 6700k.
Mainboard depends on your needs, you want to overclock ? or you want SLI ?
So you dont want overclocking your CPU, most of the time a 80-100$ Mainboard is enough and when you want to overclock get a Z170 board with the features you really need.
If you want more (streaming etc.) go for the 5820K.
32GB is not needed, even today 8gb are more then enough.
Titan X is just a waste of money go for a 980TI or wait on the Fury X2 benchmarks/prices.
PSU is way to strong, you need that for 3SLI but not for a singel GPU PC.
Tower is fine