If you're looking for a more automated process (or just don't want to mess with Excel), you can utilize the Notepad plugin options. It's as simple as using the default text editor app on your computer to open the CSV files, and enable the plugin to run the compare process. Those plugins are Compare and Beyond Compare. This is a helpful overview of how the Compare plugin can be enabled and used.
Other (non-plugin) 3rd-party options are endless. Just a few examples include:
And if you're really savvy, then you can even create a python script to run the same comparison exercise!
Choose the method that is both the right fit for your comfort level, and for the size of the dataset you are working with. But no matter what, don't waste your efforts doing one-by-one comparison by hand!