Question

Fatal error: Call to undefined method
Desbest_Showdown_Model_Mysql4_Votes_Collection::addAttributeToSelect()
in
/home/desbest/public_html/clients/magentofull/app/code/local/Desbest/Showdown/controllers/IndexController.php
on line 19

IndexController.php

public function voteAction(){
    $shake = Mage::getModel('showdown/votes')
        ->getCollection()
        ->addAttributeToSelect('*')
        ;
}

===============

code/local/Desbest/Showdown/Model/Mysql4/Votes/Collection.php

<?php
class Desbest_Showdown_Model_Mysql4_Votes_Collection extends Mage_Core_Model_Mysql4_Collection_Abstract
{
    public function _construct()
    {
        parent::_construct();
        $this->_init('showdown/votes');
    }
}

Answer 1

addAttributeToSelect() is using for EAV style model collection only (product, customer, etc.)

For other models you can use Mage_Core_Model_Resource_Db_Collection_Abstract::addFieldToSelect() method.