How to output data from module to a page. What are my options? I have some code in a module that returns some data. I want to output it in a particular place on the page: Would a block, ctools plugin for panels or a template file be the best option and how would I choose?.
If you already use Panels, and/or if you have an argument to send to your code, i'd advise Panels, definitively...

Great caching powers, multi-instances and rules of access.

But if you don't use it, don't make your site heavier with it and keep it with Blocks.

What about tpl.php ?