Las Lenas Ski Resort, Mendoza
Going to Las Leñas, even if you are not so kind skiing (like me lol), its def, a must see.
In Las Leñas you will find a great vibe very good slopes, a very interesting social life and an absolutely "no worries" policy all arround.
This year i was there for 4 weeks asisting with Argentina Alive to a company that join us to organize this trip, was an great experience and met lots of extraordinary people from all over the world.
Las Lenas is around 7 hours away by bus from Mendoza and Penitentes around 3. Las Lenas is a lot bigger with modern skilifts and a snowboard park with rails, ramps and jumps. It is quite a drive from Mendoza so you would have to stay there for at least a couple a days to take full advantage of the powder.
Penitentes is closer to Mendoza and a lot smaller, and can be done in one day.
Several agencies in Mendoza, especially in Avenida Las Heras specialize in organizing trips to both places and rent equipment.