A regular length snow jacket hits right at the hip and is the most versatile option for most skiers and riders. It gives you solid coverage over your waist and lower back without feeling bulky or restricting your movement, making it a great pick for all-mountain resort days and everyday riding.
Regular length works especially well if you wear high-waisted snow pants or a jacket with a powder skirt, since the hem overlaps cleanly and keeps snow out. You'll stay covered when you're carving groomers or hiking to a side-country stash, but you won't have extra fabric bunching up or getting in the way.
Where regular length can fall short is in deep powder or if you spend a lot of time sitting on cold chairlifts—longer jackets do a better job sealing out snow and keeping your seat warm. But if you're not chasing bottomless days or you prefer a cleaner, less bulky look, regular length is tough to beat for everyday resort use.