Multiple parameters in a List. How to create without a class?

If you are using .NET 4.0 you can use a Tuple.

List<Tuple<T1, T2>> list;

For older versions of .NET you have to create a custom class (unless you are lucky enough to be able to find a class that fits your needs in the base class library).

Another solution create generic list of anonymous type.

 var list = new[]
 { 
    new { Number = 10, Name = "Smith" },
    new { Number = 10, Name = "John" } 
 }.ToList();

 foreach (var item in list)
 {
    Console.WriteLine(item.Name);
 }

This also gives you intellisense support, I think in some situations its better than Tuple and Dictionary.

If appropriate, you might use a Dictionary which is also a generic collection:

Dictionary<string, int> d = new Dictionary<string, int>();
d.Add("string", 1);

If you do not mind the items being imutable you can use the Tuple class added to .net 4

var list = new List<Tuple<string,int>>();
list.Add(new Tuple<string,int>("hello", 1));

list[0].Item1 //Hello
list[0].Item2 //1

However if you are adding two items every time and one of them is unique id you can use a Dictionary