well, I think the Moonpark party is a terrific startup party.
I don't know how much you like Electornic Dance Music, and what are you preferred genres, but this year's been great in terms of international DJ's visiting our country, so I'm sure you'll find the option that fit you best.
MOonpark parties take place in very big warehouses, 10.000 people, maybe 15.000, going absolutely nuts. I met a few tourists in those parties, and they all were blown away by the energy of the people. Even John Digweed referred to the last Moonpark he played at, in December 2006, as his highlight for the year.
Ok, hope you have fun there!