RapidReddit for Chrome
More About RapidReddit
Posts load automatically in a stripped-down (but still very reddit-like) page that is accessible via a toolbar button. Only new posts (i.e. those not already in your browser history) are shown and they disappear after being clicked, although they are still available in the "recent" list.
RapidReddit also filters out posts that you've already seen but usually stay blue on reddit.com due to URL shortener (e.g. http://youtu.be/*) redirection.
It plays nicely with Reddit Companion, which allows a toolbar to be displayed at the top of a linked page after clicking the icon in the address bar.
Displayed posts can be limited to a specific subreddit and the time range is also configurable.