Common Entity Types

<?php

/* Nodes */

$nodeIds = \Drupal::entityQuery('node') -> execute();
$nodeList = \Drupal\node\Entity\Node::loadMultiple();

/* Node (Content) Types */

$nodeTypeIds = \Drupal::entityQuery('node_type') -> execute();
$nodeTypeList = \Drupal\node\Entity\NodeType::loadMultiple();

/* Blocks */

$blockList = \Drupal\block_content\Entity\BlockContent::loadMultiple();

/* Block Types */

$blockTypeIds = \Drupal::entityQuery('block_content_type') -> sort('label') -> execute();
$blockTypeList = \Drupal\block_content\Entity\BlockContentType::loadMultiple($blockTypeIds);

/* Paragraphs */

$paragraphIds = \Drupal::entityQuery('paragraph') -> execute();
$paragraphList = \Drupal\paragraphs\Entity\Paragraph::loadMultiple();

/* Paragraph Types */

$paragraphTypeIds = \Drupal::entityQuery('paragraphs_type') -> execute();  /* Need to test */
$paragraphTypeList = \Drupal\paragraphs\Entity\ParagraphsType::loadMultiple();

/* Users */

$userUids = \Drupal::entityQuery('user') -> execute();
$userList = \Drupal\user\Entity\User::loadMultiple();

/* User Roles */

$roleIds = \Drupal::entityQuery('user_role') -> execute();
$roleList = \Drupal\user\Entity\Role::loadMultiple();

/* Files */

$fileIds = \Drupal::entityQuery('file') -> execute();
$fileList = \Drupal\file\Entity\File::loadMultiple();

/* Responsive Image Styles */

$styleIds = \Drupal::entityQuery('responsive_image') -> execute();  /* Need to test */
$styleList = \Drupal\responsive_image\Entity\ResponsiveImageStyle::loadMultiple();