Australia hands down. Yes it's far and expensive to get there...but it will be well worth it. I did my last semester of my MBA there and it was the experience of a lifetime. Plus Bali is near so you can do a trip on the way back home. UNSW is a great school and in the heart of Sydney if you can get in. You can live at the beach and take a bus to class (approx 20min). As far as nightlife goes...well...hopefully you'll see for yourself!
I studied abroad at Bond University on the Gold Coast of Australia. I can't recommend it enough. As for proximity to surf you are very close to a handful of amazing breaks (within a 10-15 minute drive). There are buses that run from the school to town/beach but I highly recommend buying a car if you decide to go. I know it sounds crazy but a friend and I bought a used car for $2K the first month we were there and it literally made our trip. Could easily dawn patrol before class and just made the whole experience much more enjoyable. Itís a huge country with lots to see, having your own transportation made this so much easier.
The flight is crazy expensive but well worth it, like others have mentioned when are you ever going to have the chance to spend that much free time so far away. Iíd say go for it. If I happen to get laid off anytime soon I know where Iím heading for a while. Oh and also the nightlife is amazing, there is a bar on campus, the school sponsors bar crawls and runs buses to surfers paradise every weekend where you can pretty much find any type of nightlife youíre looking for. If you have any other questions feel free to reach out.
I spent a semester in Chile and got the best waves of my life. Valparaiso area has some pretty good breaks, especially just north of the city, and you can pretty easily get to a lot of very uncrowded, top-notch waves for weekend trips....Pichilemu for Punta de Lobos and Infiernillo, Puertocillo, Arica has good waves (go during the downseason unless you plan on bringing a gun). The swell window is gigantic and they get a lot of massive swells.