It's a minefield when it comes to WordPress plugins, I would say that over 70% of all WordPress plugins are awful, some are even dangerous. Horror stories of a WordPress plugin destroying your site or opening up a major vulnerabilities is nothing new.
So what can we trust in the world of WordPress plugins,
Advanced Custom Fields is pretty much a must on any WordPress site looking to grow beyond a simple blogging platform. Its easy and simple to use and allow you to add custom fields to pretty much any post type. Definitely a must have for building up a complex CMS solution with out the need to write allot of CRUD.
Ok so this next one is definetly not a plguin but will go along way to mitigating the use of plugins. I use this mainly to generate custom taxonomies and custom post types. The advantages to using actual tangible code is pretty obvious - version control.
##EWWW Image Optimizer
With the web ever increasing in size the option to one click optimize your images is a winner. This seems to be the only plugin I have found which does exactly what it says on the tin. A fast website is a happy website and a happy website ranks well.
##WP User Avatar
This is more for running a blog or managing a large user base. WordPress runs on gravitar... or something. Anyway you need this plugin in order to support avatars for your users. Simple.
Sending emails? this simple plugin makes integrating with Mandrill smtp server a painless experience. Sendgrid also has something similar which is just as easy to set up.
##XML Sitemap Generator
Again another wp-plugin which does exactly what you need it to do and that's generate an xml sitemap for your site
Comment managing is a pain in WordPress, if your not getting spammed every 5 minuets by Justin Bieber selling you UGG boots then your dealing with users forgetting a login. Disqus is 3rd party comment management application which adds another level of social media to your site. I personally don't use the plugin and instead choose to integrate it straight into the site. However the plugin does allow you to migrate comments back into your site. Lovely.
It's always good to keep on top of your social media publishing and with buffer we can have all our new content automatically distributed over several social media channels at a time we choose.
So that's what I have so far, no slide-show plugins, no form generators and no SEO plugins. Nothing which will add bloat to the head/footer of our site.
Have a suggestion, want to make the list. Send me a tweet.