First question: anytime you want. We have plenty of things to got you entertained while you're visiting us. From snow, to mountains, to rivers, lakes, sea, desert or just try Buenos Aires...
Ski--> go to the province called Mendoza, which has a place called Las LeƱas which is amazing to try! Otherwise go to Bariloche in a province called Rio *****.
Mountains--> come to Cordoba!! THis is where I do live... you have a beautiful city which is literally 20 minutes away from the pure power of our sierras... thre valleys to choose, great food and cool people!
Sea--> GO to Mar del Plata, located at the Province of Buenos Aires, the biggest place to receive you arms wide open...
Wine--> Again, go to Mendoza.... The finest places to be discovered of the wine industry are waiting for you.
City--> of course the best it's our capital, called Ciudad Autonoma de Buenos Aires, located in the province of Buenos Aires... this is the most beautiful city you'd ever met...
Try out Patagonia, the southern region of our country, I bet you whatever you want to compare it which whatever place you want and Patagonia will comfortably win! The most beautiful sights of pure nature, high mountains, virgin lakes, and lots of fine places are there!
TO your second question, you could give www.despegar.com a try, also check out our local air line called aerolineas argentinas, but you could check out your airlines, a discount ion this subject would be offered by anyone...
To your third question.... the flight takes about 12 hours.... pretty long ride, I know, but so well worth!!
And your last question is the hardest.... as I said in the first one... whenever you arrive, you will always be entertained and amazed by our country...
Please come to visit us...