This question is more a matter of personal preference, what you need, and budget.
Most "good" email marketing automation tools can handle very similar situations like tracking and reacting to clicks, on page activity, replies, and beyond. And, of course, they all have their unique ways to handle each situation. So, it becomes more of a question of ... what makes sense to you and how your brain functions.
Figuring out which tool is the best for you also depends on what you need. For example, if you need a Customer Relationship Management (CRM) tool for your business ... this can impact the email marketing automation tool you choose.
Finally, some email marketing automation tools cost thousands of dollars a month ... and they might actually be "the best"; however, if you can't afford it ... it doesn't matter. So, you'll need to find an email marketing tool that also fits into your budget. And, of course, utilize it so it pays for itself. These types of tools better pay for themselves, if not, you'll need to evaluate how your using it and if it's worth your time and money.
Needless to say, the "best" tool for you may not be the "best" tool for me.
ActiveCampaign feels "right" to me, it does everything I need, and it's affordable.
Zapier is a 3rd party tool that allows me to connect my sites to ActiveCampaign in a myriad of ways ... it's super helpful!
In closing, most email marketing automation tools have free trials. Find a few that fit your price range and offer what you need, and test them out. Figure out which ones feel "right" to you!