Best class to store class models

each one  serves purely different purposes
List  :-  Add,Remove,Count and Loop through (So can never be used in UI, anybody can manipulate data, the sole pupose of UI is to Loop through a collection or take user inputs and send to Business layer, in business layer you can use List but not in web form's code behind or MVC controller, it is wrong architecture) .
 
IEnumerable:- just loop through collection (Best suited for UI (Controller,web form's Code behind))
 
IQueryable:- Gets filtered data from database (best for search functionality in business layer)
 
ObservableCollection:- To notify if data is manupulated inside collection.(use it accordingly)
 
In short , no collection is better than others each have different purpose, otherwise microsoft dev is not a fool who will create so many collections for nothing.