depends on what you want to do - really.

at the airport they offer free T1 connectivity to the internet, so that is a way to kill time.
or else they have all sorts of offers for transit passengers - pick up from the airport, drop off to various points of interest, etc. they will store luggage for you for a very low fee.( i think there is early checkin as well)

nightlife is varied, but a little too regimental. the food is excellent - arguably the best in the world.
hope this helps.
overall a great place to do a layover. enjoy