The Kindle Fire doesn't have 3G but has lots of other things.
I have the Kindle Touch 3G because all I really want to do is read.....it does have some of the newspapers on as well. I don't have to search for places with WiFi when I'm away or out and about cos the 3G does that for you and downloads anywhere. I'm not bothered about watching movies, etc. so this suits me perfectly. It's great not having to search for WiFi hotspots when you're out.
The Kindle Paperwhite I believe won't be available over here until about December and you can get a 3G version of that.
A little write-up about the Kindle Touch 3G........
Easiest to Use, Free 3G Wireless for downloading books anytime, anywhere
Kindle Touch 3G is our easiest-to-use, most-convenient Kindle because there is no wireless setup--you are ready to shop, download, and read right out of the box. Kindle Touch 3G uses the same wireless signals as mobile phones, so you don't need to worry about Wi-Fi connections, passwords or internet charges. Unlike mobile phones, with Kindle Touch 3G there are no monthly fees or commitments — Amazon pays for Kindle Touch 3G's wireless connectivity.
It really depends what you want the Kindle for I suppose. If you want all the 'bells and whistles' but aren't bothered about the ease of downloading, then it's the Kindle Fire or one of the original Kindles for you but if you want to read and not be bothered about finding WiFi hotspots then the Touch 3G is superb.