You can pull certain tricks with ballistic delivery methods. A depressed trajectory (flatter profile, lower apogee) would give you the option of coming in through a window, with an additional benefit in that it would be harder to intercept the payload.

You would also need to limit this strategy to payloads that can withstand shock loads of multiple hundreds of G (soups and hard cheese, maybe even bread adequately packaged. may need a different method for floral deliveries).

Proof of concept shouldn't be too difficult, most of the tech already exists (Raytheon and Northop-Grumman have had a handle on it for decades). DHS might not be too amused, however.