If I had 1,000 lindens...I would first buy my own land and then block it off so that no one could enter besides me.  I always get annoyed by blocked off land because it usually looks like something I would want to explore.  I would make myself a house that looks like a huge castle.  I would also make my own clothing or buy some clothing that I find around Second Life.  I wouldn't buy a lot of clothes though, because I found a place in Second Life where clothes are for free, so why waste my money?  I would also furnish my house and make it exactly how i wanted it to look.