I have a List someList.
List someList
class MyClass { public int Prop1... public int Prop2... public int Prop3... }
Just use the build-in function DistinctBy of Microsoft Ajax Ultility library like the sample blow:
First including library
using Microsoft.Ajax.Utilities;
then
var distinctList = yourList.DistinctBy(x => x.Prop2).ToList();