Colleagues sometimes ask for advice on Wordpress plugins. I have three guidelines when considering a plug-in:
That being said, here is my list of favorites.
Code Embed
Embed HTML and Javascript in your web pages. This is what I use for secondary menus on web pages. For those of you who grew up using "include" files on static web pages, this is the Wordpress equivalent.
Column Shortcodes
Add responsive columns to any page or page segment. Example: [1/2][1/2} for two equal columns. Columns stack vertically on small screens.
Content Views
Flexible display of recent posts. I like to use this for a 3 column wide grid of snippets of recent posts. Much more attractive than a linear list of recent posts. Can filter by category.
CSS Hero
Extremely handy for finding what CSS elements control a feature. Lets you tweak appearance with easy tools, and then generates the CSS for you. Used as intended, it will make all the needed changes for you.
However, let me share my idiosyncratic use of CSS Hero. I do not like to rely upon CSS Hero to control my site's appearance, just to help me determine the CSS I need. So instead of letting CSS Hero control the layout permanently, I copy the code it generates into a child theme styles.css fileor into the theme "additonal css". Then I exit CSS Hero without saving changes (or rather, not saving changes within CSS Hero.) This may seem paranoid, but I sleep better depending on one less plugin for my site to function.
Display Posts Shortcode
Place a list of recent posts (by category if you like) on any page. See also Content Views plugin above, which is more flexible and I think more attractive.
GA Google Analytics
Adds your Google Analytics tracking code to every page. Low overhead.
Google Photos & Picasa Viewer Pro
Add a photo album anywhere. Create your photo album on Google Photos, and this plugin will insert the album anywhere. Several choices of layout. (Yes, I know Picassa is dead; it only lives on in the name of this plugin.)
Google XML Sitemaps
Creates a good XML sitemap for your site to aid in indexing by search engines. Low overhead. (See also The SEO Framework below.)
Imsanity
Downsizes and recompresses images upon uploading. Do not let huge images slow down your site!
Redirection
Find 404 errors and redirect them to the page of your choosing. Supports regex wildcards.
Responsive Image Maps
Makes images responsive in places (such as Tablepress tables) where they would otherwise not be.
Simple Calendar
Add the contents of a Google Calendar anywhere.
Simple Image Sizes
Add more options in media setting page for image sizes.
Tablepress
Provides rich support for tables. However, table content is not necessarily WYSIWYG for adding images to tables.
The SEO Framework
Automatic SEO enhancement. I use this and Google XML Sitemaps plugin in lieu of Yoast. I think this combination generates less overhead.
WP Google Search
Adds Google Search to your website.
WP Super Cache
Speeds up your website, lessens load on your server.