What are the best financial templates to use for a startup?

You might try www.mrexcel.com. Look in their items for sale although you could start in the user forums.
I have used the site mostly for help in figuring out how to do something using an Excel function, but they have a number of financial templates available for purchase.

An advantage to purchasing templates as opposed to finding free one somewhere is that the site backs up the accuracy of the templates.

You will have to do some digging,

Also Microsoft itself has Excel user downloads for the asking.

Good luck

SRMORGAN

Full disclosure—I work at Profitably but we’ve been building out a web app that does just this.

Our planning tool is free (forever), and was built under the premise that we’re all good at Excel but you should spend your time building your business, not your spreadsheet—you can check it out here

We also make an analytics app that will show p&l, customer profitability, cash flow, etc. Send me a message if you’re interested in hearing more.