Fokker 70 - heading towards retirement, no hull losses yet (but less than 50 built).
For currently operating types, if you get into sub-types and define "no hull loss" as "no hull loss in commercial flight operations", then I think the 717, 737-600, 737-900, 777-300, E145, E170, A318, A319, A330-300, A340-200, A340-500 and A380 all have perfect records so far - touch wood.
Of these, perhaps the A319 has the most impressive record: over 1300 built, and nobody's managed to seriously prang one yet.