Since seeing bus 197 recommended here a few years ago, I've not travelled from the airport to the city centre by any other means. It's so easy and convenient.
But, I always recommend to first time visitors that they use the train and tram combo.
That first time walking out of Centraal station is such a thrill. The noise, the crowds, the bicycles and trams flying everywhere.
It's easy catching the tram outside the station to get to Leidseplein and you get your first tantalising glimpse of the city centre as you ride along.
Bus 197 is great but you only really get to see the suburbs and a quick look at Museumplein.