How do I display todays date on SSRS report?

You can also drag and drop "Execution Time" item from Built-in Fields list.

date column 1:

=formatdatetime(today)

Try this:

=FORMAT(Cdate(today), "dd-MM-yyyy")

or

=FORMAT(Cdate(today), "MM-dd-yyyy")

or

=FORMAT(Cdate(today), "yyyy-MM-dd")

or

=Report Generation Date: " & FORMAT(Cdate(today), "dd-MM-yyyy")

You should format the date in the same format your customer (internal or external) wants to see the date. For example In one of my servers it is running on American date format (MM-dd-yyyy) and on my reports I must ensure the dates displayed are European (yyyy-MM-dd).