I wanted to write something that actually took advantage of the language features. I made a separate Binge class that handles the output of the song. It's provided with a delegate to do the actual output, and it fires an event when there are no more bottles. It also accepts a name for the drink, other than beer, and a starting count. It even outputs "bottle" when the count is one!

The source to the class is below, and you can even watch it run!

/// Implementation of Ninety-Nine Bottles of Beer Song in C#.
/// What's neat is that .NET makes the Binge class a
/// full-fledged component that may be called from any other
/// .NET component.
///
/// Paul M. Parks
/// http://www.parkscomputing.com/
/// February 8, 2002
///

using System;

namespace NinetyNineBottles
{
   /// <summary>
   /// References the method of output.
   /// </summary>
   public delegate void Writer(string format, params object[] arg);

   /// <summary>
   /// References the corrective action to take when we run out.
   /// </summary>
   public delegate int MakeRun();

   /// <summary>
   /// The act of consuming all those beverages.
   /// </summary>
   public class Binge
   {
       /// <summary>
       /// What we'll be drinking.
       /// </summary>
       private string beverage;

       /// <summary>
       /// The starting count.
       /// </summary>
       private int count = 0;

       /// <summary>
       /// The manner in which the lyrics are output.
       /// </summary>
       private Writer Sing;

       /// <summary>
       /// What to do when it's all gone.
       /// </summary>
       private MakeRun RiskDUI;

       public event MakeRun OutOfBottles;


       /// <summary>
       /// Initializes the binge.
       /// </summary>
       /// <param name="count">How many we're consuming.</param>
       /// <param name="disasterWaitingToHappen">
       /// Our instructions, should we succeed.
       /// </param>
       /// <param name="writer">How our drinking song will be heard.</param>
       /// <param name="beverage">What to drink during this binge.</param>
       public Binge(string beverage, int count, Writer writer)
       {
           this.beverage = beverage;
           this.count = count;
           this.Sing = writer;
       }

       /// <summary>
       /// Let's get started.
       /// </summary>
       public void Start()
       {
           while (count > 0)
           {
               Sing(
                   @"
{0} bottle{1} of {2} on the wall,
{0} bottle{1} of {2}.
Take one down, pass it around,",
                   count, (count == 1) ? "" : "s", beverage);

               count--;

               if (count > 0)
               {
                   Sing("{0} bottle{1} of {2} on the wall.",
                       count, (count == 1) ? "" : "s", beverage);
               }
               else
               {
                   Sing("No more bottles of {0} on the wall.", beverage);
               }

           }

           Sing(
               @"
No more bottles of {0} on the wall,
No more bottles of {0}.", beverage);

           if (this.OutOfBottles != null)
           {
               count = this.OutOfBottles();
               Sing("{0} bottles of {1} on the wall.", count, beverage);
           }
           else
           {
               Sing("First we weep, then we sleep.");
               Sing("No more bottles of {0} on the wall.", beverage);
           }
       }
   }

   /// <summary>
   /// The song remains the same.
   /// </summary>
   class SingTheSong
   {
       /// <summary>
       /// Any other number would be strange.
       /// </summary>
       const int bottleCount = 99;

       /// <summary>
       /// The entry point. Sets the parameters of the Binge and starts it.
       /// </summary>
       /// <param name="args">unused</param>
       static void Main(string[] args)
       {
           Binge binge =
              new Binge("beer", bottleCount, new Writer(Console.WriteLine));
           binge.OutOfBottles += new MakeRun(SevenEleven);
           binge.Start();
       }

       /// <summary>
       /// There's bound to be one nearby.
       /// </summary>
       /// <returns>Whatever would fit in the trunk.</returns>
       static int SevenEleven()
       {
           Console.WriteLine("Go to the store, get some more...");
           return bottleCount;
       }
   }
}