excel.vim (GitHub: yakiang / excel.vim, License: MIT) by Yakiang Zhong is a Python-based script that can display the data from an Excel file. You can install the necessary Python module with
pip install xlrd, and it will display each worksheet as a separate tab which is cool.
I'm one of those people that opens everything in Vim, so I quite like the idea of this plugin.
ExtractLinks by Ingo Karkat helps manage long links in arbitrary text snippets. If you're writing a Markdown file, or a comment for a post on a site like Stack Overflow, then
:ExtractLinks can help manage lists of references to keep the text tidy.
Ingo notes that this plugin was inspired by Links to references in Mutt or Vim on Super User, and I can imagine it being really useful for writing text emails.