Facebook Like, Page Links To, (great for various redirections), Simply Exclude, (exclude certain posts and categories from your front page), WordPress Mobile Edition, etc... Your list is based on what?
Exactly. Even my blog has slow loading speed by using more than 10 plugins. I'm dis-activating useless plugins...
That is because it is a so-called "premium" plugin and you need to purchase it. There are a number of these in that list, and NONE OF THEM are "must use" plugins. Most of these plugins prey on people who are obsessed with SEO and think that just by adding a free or premium plugin is some magic pill that will boost their traffic. People spend more time chasing after these magic pills when they should be putting more effort into the number one SEO tactic they can control -- writing good content and titles. You can add all the plugins you want, shell out a lot of money and time, and still not have anything worth getting into search to begin with.
A true statement to be said here is too many plugins will slow a site down. I agree that most of the plugins will not be needed and should only be looked at if useful to the niche of your blog. I don't know as to why the list was made, but plugins are not a must use product. They can in fact be helpful however.
from that 20 plugins you do not mention akismet , one of most powerfull anti spam. Also its free. I want to add more, another one plugin maybe you need to try is "search terms tagging 2", this really good for SEO purposes as i know.
Auto backup to email - WordPress Database Backup. I like also 404-to-start - very simple and effective.
I think you need to rephrase your wording from "you must use" to "may want to consider". You do not have to use any plugins at all. The less the better, as far as I am concerned. Also, how did you determine popularity? Some of those plugins I have never heard of before. Then you are missing the truely popular pseudo-must-have plugins such as Akismet, Contact Form 7, WP Super Cache, and WP-DB-Backup to name a few.
WordPress Database Backup – This plugin is a life saver when things go wrong! It allows on-demand backup of your WordPress database. Search Engine Optimization (SEO) WordPress SEO by Yoast – Yoast’s all in one SEO solution for your WordPress blog: SEO titles, meta descriptions, XML sitemaps, breadcrumbs & much more. All in One SEO Pack – Out-of-the-box SEO for your WordPress blog. If you are using the “WordPress SEO by Yoast†plugin then don’t install this one. Google XML Sitemaps – This plugin generates a XML-Sitemap compliant sitemap of your WordPress blog. This format is supported by Ask.com, Google, YAHOO and MSN Search. Blog Statistics Related Google Analytics for WordPress – This plugin makes it simple to add Google Analytics with extra search engines and automatic clickout and download tracking to your WordPress blog. WordPress.com Stats – Tracks views, post/page views, referrers, and clicks. This plugin requires a WordPress.com API key to function. Caching Plugin W3 Total Cache - The fastest and most complete WordPress performance optimization plugin. After you use the w3 total cache plugin you won’t go back to using WP Super Cache. WP Super Cache - WP Super Cache is a static caching plugin for WordPress. It generates html files that are served directly by Apache without processing comparatively heavy PHP scripts. By using this plugin you will speed up your WordPress blog significantly. Blog Security WP Blog Security Tips – This is not a plugin but all the tips mentioned here should help you securing your WordPress blog. LoginLockdown – Login LockDown records the IP address and timestamp of every failed WordPress login attempt. If more than a certain number of attempts are detected within a short period of time from the same IP range, then the login function is disabled for all requests from that range. This helps to prevent brute force password discovery. E-commerce, Paypal Donation and Payment WordPress Simple Paypal Shopping Cart – is a very easy to use plugin that allows you to sell products or services online in one click from your WordPress blog. Very useful when you want to sell eBooks or digital products from various posts and pages and need a WordPress Shopping Cart solution. WP Easy Paypal Payment Accept – This is a very easy to use WordPress plugin to Accept donation or Paypal payment for a service or a product in one click. Handy when you are trying to put a customized donation option in the sidebar of your blog. WordPress eStore – This plugin provides a complete solution to sell digital products securely from your wordpress blog. Membership Plugin WordPress eMember – WordPress eMember is a membership plugin that can turn your existing or new WordPress site into a membership site easily. RSS Subscription Related FeedBurner FeedSmith – This plugin detects all ways to access your original WordPress feeds and redirects them to your FeedBurner feed so you can track every possible subscriber. Add to Any: Subscribe Button – Helps readers subscribe to your blog using any feed reader. Category Specific RSS Menu – A simple WordPress plugin to add category specific RSS subscription menu into your posts, pages, sidebars. Very handy when your blog covers multiple topic from non related subjects. This plugin was developed by me. Contact Forms Related Contact Form 7 - Contact Form 7 can manage multiple contact forms, plus you can customize the form and the mail contents flexibly with simple markup. The form supports Ajax-powered submitting, CAPTCHA, Akismet spam filtering and so on. cforms – cforms II is the most customizable, flexible & powerful ajax supporting contact form plugin. WP Contact form – WP Contact Form is a drop in form for users to contact you. Social Networking Sociable – Automatically add links to your favorite social bookmarking sites on your posts, pages and in your RSS feed. Share This – This is a very useful plugin that allows your visitors to share a post/page with others. Supports e-mail and posting to social bookmarking sites. Fat Free WordPress Social Share Buttons Plugin - This is a very simple and FAT FREE share button plugin that adds Google plus one, Facebook and Twitter share buttons to your blog posts. For Google Adsense Simple Google Adsense insertion – Easy to use WordPress plugin to insert Google Adsense to your posts, pages and sidebar. This plugin was developed by me. Adsense-Deluxe – Place Google AdSense ads in your WordPress Posts. Capable of handling complex adsense management. Other Very Useful Plugins Simple Tags – This is one of my most favorite plugins. It makes my WordPress Tagging life so much easier. It helps with Auto completion, Suggested Tags, Tag Cloud Widgets, Related Posts, Mass edit tags. Executable PHP Widget – Like the Text widget, but it will take PHP code as well. Very handy for inserting custom ‘php’, ‘html’, ‘javascript’ in the sidebar. WordPress Newsletter subscription – Creates a simple form to collect subscription requests to newsletter software managed mailing lists. WP-Polls – Adds an AJAX poll system to your WordPress blog. Allows you to easily include a poll into your WordPress’s blog post/page. No Self Pings – This plugin does exactly what the name suggests. Exclude Pages – This plugin lets you manually exclude WordPress pages from the navigation menu. Comes in handy when you are trying to create hidden pages. WP Smush.it – This WordPress plugin reduces image file size and improve performance using the Smush.it API within WordPress. Everytime you upload an image to your media uploader this plugin will automatically compress the image without losing quality!