Thumb of rule related to plugins
1) I do not add plugins that have not been updated for more than 1 year. If my website have plugins that are older than 1 year I replace them with a updated wordpress plugin.
The top 5 would be
Contact Form 7 One way to keep spammer from spamming your email box.
Really Simple CAPTCHA This keep those bot from sending you spamming email
Oh yes and Backup you don’t want to lose your hard work. Don’t you?
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