x => x * x						
x => { return x + 1; }
(int x) => x + 1	
 (int x) => { 	int max=0;
			. . .
			return x + 1; 
}
(x, double y) => x * y					
() => Console.WriteLine()		
      int Cube(int x) => x * x * x;         // с версии 4.6
Пример: 
 delegate bool FilterDel ( int  element);
 static void PrintData ( int[ ] d, FilterDel  del)   {
            foreach ( int di in d)
                if (del(di)) Console.WriteLine(di);
 }	
 . . .
 	     int [ ] data = { 1,4,12,8,7,9,5 };
            FilterDel  filter =  x=> x%2==0 ? true : false;
            PrintData(data,  filter);
или 
	     int [ ] data = { 1,4,12,8,7,9,5 };
            PrintData(data,  x => x%2 != 0 ? true : false);