The last two make it appear that you're screaming. :)
I currently have 3 unanswered emails at work from the past week (all to the same person) and I was very tempted to reply with that this morning. Instead, I took the diplomatic approach and responded to the most important email, acknowledging that she's busy. Then I combined all the things I need a response to into that one email. "Reminder" will be plan B.
*edit to add: Her response was great! Basically, she said we have to pay up if we want a faster response. LOL
Not sure if the text here is large enough to read, but here it is. :)))
If you right-click and download the image, you can probably see it better.
RE: A polite reminder