I LOVE this plugin, and I really love the dedication and considerate nature of the developer. Tablepress creates perfect tables that can easily be sorted (alphabetical order or whatever) without having to completely rearrange any html in a post (I hate straight html tables!). It's especially helpful if you have a table you're adding to regularly (we have an ongoing list of books on a page in our site), and it's sooooo easy to add/delete/hide rows and columns --- the hidden columns come in handy to alphabetize tables where the first column is hyperlinks.
Aside from all that (and the fact that it's free!), I was incredibly impressed with how great the developer was when he issued a complete redesign. He included in the new version functionality necessary to import from the old version, so none of us lost or had to manually rebuild anything. And he gave perfect step-by-step, made-for-dummies instructions. I never would have figured it out on my own! Not only has he developed a great plugin, but he made absolutely sure even the most technically challenged can benefit from it.