This is the only one you need.
Games don't actually tax the system to its fullest. My last reading off the socket was actually lower than the lowest estimate I could get from this... Which isn't a bad thing. But to help...
- Put everything in there. At the bottom right, adjust for 100% load and 10% capacitor aging.
- Round up to the nearest 50W. Then get a power supply that's 50W-100W higher than that
So for instance, if you have power requirements at 423W and 483W, these would convert to 450W and 500W after rounding, then you would get something that was between 500W-550W and 550W-600W respectively.
Power supplies are most efficient around 50%-60% load and considering that every time I measured it and tried to tax the system under the most stressful, nominal load (that's not a burn in test, as that isn't a typical usage case) is often around 50%-60% of what that calculator estimates... that's about as good as you'll get.
This also gives you room to upgrade, but normally most video cards and CPUs don't chew more power with subsequent generations.