I would like to turn off recommendations in my omnibox/searchbox. Specifically from history (e.g. disabling typing f to automatically bring up facebook.com).
I find the suggestions distract me often and I don't really need to get to facebook.com 2 seconds faster.
It is possible to permanently turn off predictions from google and the web, however predictions from your browsing history can't be turned off. You can temporarily stop them from appearing by deleting your browsing history or using incognito mode (CTRL+SHIFT+N).
To turn off web predictions:
You can also try installing the "No History" extension in chrome which will prevent chrome from collecting any history and thereby stopping the predictions, however the downside is you wont be able to view your browsing history at all.
A partial solution for Version 73.0+ (no search suggestions but still get url history) is to change the default search engine, since the omnibox prediction service is no longer toggleable from the "Privacy" settings panel.
Just go to the "Search Engines" panel, and change the default engine to your prefered provider
chrome://settings/searchEngines
If you wish to keep google but without "search suggestions" you may use this:
{google:baseURL}search?q=%s&hl=en
This will suggest from your URL history instead of predicting a search with "useful" images, products, video or news snippets.
In Chrome 92 you can turn it off by going to about:settings->Sync and Google services->Other Google services->Autocomplete searches and URLs. Turn that off. Chrome will still show completions from history but not from the web AFAICT.