Good and bad examples of using the var keyword in C#

UsingVar.cs

// good design
var numbers = new int[] {1, 2, 3, 4};
var stringBuilder = new StringBuilder();
var letters = new List();
var keywords = new Dictionary();

// OK (but prefer explicit declaration)
var pages = 10; // int, long, what to expect?
var username = "Kevin";
var order = GetOrder(orderId); // ok if the type is Order, otherwise not
for (var x = 1; x < 10; x++)

// bad design
var settings = GetInboxSettings(); // not obvious at all
var userId = GetUserId(); // ambigous, is this guid, string, int or a custom UserId object?
Dictionary orders = new Dictionary(); // redundant