I fly into Santiago next May and have two and a half months in South America.
I'll be traveling mostly by bus, but am wondering whether I should fly out of Rio or Lima??
I'm up for trekking, national parks, good food and wine, snowboarding and a few of the well known spots (Iguassu, Salt Lakes, Pantanal, Lake titicaca, nazca etc.)
Anyone suggest a good route?
You could take a bus from Santiago to Arica (town at the Peruvian border) this takes about 25 - 30 hours. Then get a colectivo taxi across the border to Tacna (Peruvian border town), then a bus to Arequipa. From here you can get connecting buses to Nazca, Lima and Cuzco.
From Cuzco you can get a bus to La Paz, where you can do lots of excursions like the death road, trips out to the salt flats etc.
When I was in Cuzco I went into the Bolivia tourism centre and they were offering flights to Sao Paulo for $89 USD, which is a pretty good price. It might be worth checking the place out when you go to Cuzco and see if they have any similar offers. From SP it takes about 14 hours to Iguacu on a bus, or 6 hours to Rio. If you don't fancy taking a plane to Brasil you could look into buses. I met a guy who had been travelling in Bolivia and I think he said, if I remember correctly, he got a bus from Santa Cruz, Bolivia down to Cordoba. From Cordoba there are buses to Buenos Aires and to Iguazu.
Also, if you like good wine then I'd recommend a few days in Mendoza, the main city for wine in Argentina. I stayed in a HI hostel on Rua Espana. The staff are very helpful and help you book excursions. Mendoza is about 7 hours on a bus from Santiago. Try and take the bus during the day so you can see things out of the windows. The bus goes through the Andes and the views are quite picturesque.
Hope this helps.