The terrace of LEF is the best terrace of Delft. This was announced by the technical university (TU) at Delft. They wrote:
Doelenplein is the prettiest square of Delft. Not surprisingly. Many tourists, students and some yuppies meet on the terrace of LEF. Under the coloured lights in the plane trees and has wonderful views of the canal. The trees provide shade, but it is easy to find a sunny table in the afternoon and evening.
The drinking menu is extensive and has a lot of nice drinks. Also for your dinner this is the best terrace of Delft. The service extremely quick, polite and attentive.