Well, that seems like a reasonable request, but it's not that easy. Firstly, the name of an email sent is not a value on any field in the lead database. Rightfully so, as one person receives many emails, and 1:n relationships never work well in lead fields.
You could e.g. create a field like "Last Email Sent" and use the trigger.name token to copy the name of an email into that field.
Or, you check out "People Performance Reports" with Custom Columns, and created Custom Columns for the various email variants (Smart List: Was Sent Email abc..., Name that Smart List after the Email it is filtering on and bring that onto your report as Custom Column)
Or you just create Smart Lists that filter on the various emails sends and monitor your recipients this way.
Overall, I admit, just workarounds, but I don't see any native function that would allow the view that you're expecting.