Which to use Arrays, Collections, Lists and Generics

Hi all, firstly, please try to remember that the Unity team themselves use Collections :)

From a coding point of view this to me is the most important decision to make in how I code i.e. what to use for set processing. I know the opinion of some but I'd like the communities' thoughts, the reason is because I need to make a decision for how to direct a team of devs to do this on a commercial game.

I'd like some help on this, for the code listings below, the array version seems to be 1.5x faster than the List version but I personally believe that the List version is better and less coding, which should I use the array versions or the List versions to find / see if objects exist in a set and then work with them. I personally don't think the difference is any big deal compared to other performance issues like models, textures and lighting / shaders. The Generics version is a lot less code and more modern / recommended by the .NET team. Please let me know your recommendations.

Cheers.

using UnityEngine; using System.Collections; using System.Collections.Generic; using System.Linq; using System; using System.Diagnostics;

public class DynamicMegaMod : MonoBehaviour {

 private bool Exists(int val, MyClass[] search)
 {
     foreach (MyClass i in search)
         if (i.MyValue == val)
             return true;
     
     return false;
 }
 
 private MyClass Find(int val, MyClass[] search)
 {
     foreach (MyClass i in search)
         if (i.MyValue == val)
             return i;
     
     return null;
 }    
 
 public class MyClass 
 {
     public int MyValue { get; set; }
     public string AnotherValue { get; set; }
     public string AnotherValue2 { get; set; }
 }
 
 // Use this for initialization
 void Start () {        
     System.Diagnostics.Stopwatch sw1 = new System.Diagnostics.Stopwatch();
     
     //trying to find if an element exists in an array of 100000, 10000 times
     sw1.Start();            
     
     MyClass[] myArray = new MyClass[100000];
     
     for (int i = 0; i != 100000; i++)
         myArray[i] = new MyClass() {MyValue=i};
                 
     for (int i = 0; i != 10000; i++)
     {
         if (Exists(50000, myArray))
         {
         }
     }
 
     sw1.Stop();                    
     
     System.Diagnostics.Stopwatch sw2 = new System.Diagnostics.Stopwatch();
     
     //trying to find if an element exists in a list of 100000, 10000 times
     sw2.Start();
     
     List<MyClass> myList = new List<MyClass>(100000);
     
     for (int i = 0; i != 100000; i++)
         myList.Add(new MyClass() {MyValue=i});                
         
     for (int i = 0; i != 10000; i++)
     {
         if (myList.Exists(mv => mv.MyValue == 50000))
         {            
         }
     }        
             
     sw2.Stop();    
     
     System.Diagnostics.Stopwatch sw3 = new System.Diagnostics.Stopwatch();
     
     //trying to find an element in an array of 100000, 10000 times
     sw3.Start();
             
     MyClass[] myArray2 = new MyClass[100000];
     for (int i = 0; i != 100000; i++)
         myArray2[i] = new MyClass() {MyValue=i};
                 
     for (int i = 0; i != 10000; i++)
     {
         if (Find(50000, myArray2) != null)
         {
         }
     }
 
     sw3.Stop();                    
     
     System.Diagnostics.Stopwatch sw4 = new System.Diagnostics.Stopwatch();
     
     //trying to find an element in a list of 100000, 10000 times
     sw4.Start();        
     
     List<MyClass> myList2 = new List<MyClass>(100000);        
     
     for (int i = 0; i != 100000; i++)
         myList2.Add(new MyClass() {MyValue=i});                
                 
     for (int i = 0; i != 10000; i++)
     {
         if (myList2.Find(mv => mv.MyValue == 50000) != null)
         {            
         }
     }        
             
     sw4.Stop();            
 }
 
 // Update is called once per frame
 void Update () {
     
     /* do something */
 }

}