Watts work fine for AC - multiply your RMS voltage by current. The RMS takes care of the fact that AC isn't steady like DC.
VA (takes power factor into account) is relevant for sizing transformers, breakers, wiring, etc but usually only affects your bill if you are a large industrial customer.
That is just what I said: that is the formula for VA, not P, even though both have the same dimensional units: https://en.wikipedia.org/wiki/Volt-ampere and https://en.wikipedia.org/wiki/AC_power#Apparent_power. And they'd be roughly the same for something like a toaster, but if you happen to be interested in, say, the billed power consumption of a 30 year old fridge with a motor
Can't edit any more, but yes I see your point now, and my earlier comment was wrong; you can't get the watts of an AC device by multiplying RMS voltage and current. That will indeed give you VA. Watts = VA * power factor, to get real power. VA is always apparent power.
VA (takes power factor into account) is relevant for sizing transformers, breakers, wiring, etc but usually only affects your bill if you are a large industrial customer.