Feed My Inbox is an RSS-to-email service, and I used it for all of my RSS reading. The default delivery will group several recent posts in to a single email.

However, they've recently added a "One post per email" option that allows for seamless feeding to my Remember the Milk. (Note that this feature is only available for paid FMI subscriptions.)

For instance, I've added personalized feeds for:
    •  MyEpisodes.com — for my favorite TV shows airing today
    •  Grooveshark / Last.fm — for my favorited songs, which I use to research new artists or add songs to my iTunes want list
    •  Instapaper.com — for certain pages with video or interactivity that I don't want to view on my iPhone or Kindle

Within FMI, I've customized the name of the RSS feed with RTM Smart-Add parameters (due date, priority, etc.). Then, I've used Gmail to selectively filter the feeds I want to send to RTM.