using System;
using System.Linq;

public class Program
{
    public static void Main()
    {
	    var table = new[] { 
            new { id = 1, val = 6, sym = 'ф' },
            new { id = 1, val = 7, sym = 'ы'  },
            new { id = 2, val = 9, sym = 'в'  },
            new { id = 2, val = 3, sym = 'а'  }
        };
        
        var q = from row in table
                group row by row.id into gr
                select (from row in gr
                        orderby row.val descending
                        select row
                ).First();
                
        foreach (var row in q)
            Console.WriteLine(row);
    }
}