Do you mean one door for fridge on top; separate door for freezer on bottom? Or do you mean one door that opens to both the refrigerator and to the freezer at the same time? If you mean the first option, there are dozens and dozens.

I think there are a lot of those out there. Ours is a Whirlpool Gold. Although we never use the icemaker, it does have one. From the Whirlpool site:

I have a Maytag -- bottom freezer, with icemaker, single door on top. It's been great for 3 years.

It would be great if you could clarify. Are you looking for a freezer that has a door and not a drawer?

My Sub-Zero BI-36U has a single door fridge over a drawer freezer with ice maker. Love it.

I have an LG single door with bottom freezer. It is made as a freezer swing door or a drawer (or at least was when I got mine). I have the drawer and I am very happy with the fridge, freezer and the ice maker (has three cube sizes and a setting for making faster ice.). At the time, virtually the same fridge was also sold under the Kenmore name.