Only a little off the beaten track
There isn't the "wow" factor of Wat Pra Kaew (the temple of the Grand Palace) but the Italian marble and stained glass windows gives the place a unique character. When in Bangkok, it is easy to overdose on temples (buddha sitting down, buddha standing up, buddha lying down, etc. etc.) but you will see something here that you won't at any of the other temples: a tasteful elegance, rather than every spare inch plastered with gold leaf; and fountains, water features and benches just to sit down and enjoy the beauty of the place. Because it is just off the tourist trail, you will also find that this place is not as crowded as many of the others. This is also the temple at which the current king (Rama IX, Bhumibhol Adulyadej) was himself a monk in his youth.