I feel your pain.
In fact, based on this list:
... it seems impossible to choose. :)
The answer will follow:
"Who will be getting it done - doing the work?" (low skill? high skill?)
"Will you be integrating it with other tools?" (for automation)
"Is power / flexibility more important? or simple/fast?"
I like HubSpot because it is an all-in-one solution with all the marketing tools integrated into one. It is simple to use without coding or can be used by the coders and designers. It is a rocketship!
Mailchimp is a good way to get started. This is because of how simple it is to learn. (for an email system) and so many people use it, it is easy to get help/assistance when needed. It also integrates with many other tools you will be using.
While I have not tested it yet (newer email), Wix ShoutOut looks very promising. It looks as simple and smooth at MailChimp.
The struggle with email for many is the design. Fortunately the tools above keep it fast, easy simple.
Lorne has a good point. "getting emails via a form" - all three tools above offer forms you can embed into your website - with a copy/paste.
There are other free email options on the "best on the planet list" - Mailchimp starts at free if every penny counts.