Did both this Jan. Niseko: better snow, English everywhere, 2x the price. Hakuba: more terrain, more Japanese hosts, longer travel from Tokyo. If it's your first Japan ski trip: Hakuba. If you have 7+ days and don't want to think: Niseko. AMA.
>>1 Counter: stay Tokyo nights, day-trip Yuzawa. 2 hrs by Shinkansen, half the lift price.