Crashes @ Building Terrain

Just downloaded Minecraft ($27) and have not even been able to play! I select 'single player'' then 'create new world' it launches, then gets stuck/freezes @ 'building terrain' I then am only able to close via the Task Manager. So frustrating. I have deleted and tried re-dloading to no avail. I DO have the most recent Java version. Not sure what the problem is, please advise.
/thanks