Consider these completely free-to-use for non-commercial ventures.
1 - Hidden Shrine
This is a concept that fascinates me in dungeon design, the idea of rooms that are totally sealed off from the rest of the dungeon, perhaps only accessible by magical means or from a higher or lower level. So what's so special or dreadful about the statue that is has to be sealed in like this?
2 - Golgotha Heights
Split into two to prohibit N/S egress (assuming you don't rotate the geomorph 90 degrees). The curious spur near the middle is either a cave-in or an unfinished passageway.
3 - Hypostyle Halls
What's a hypostyle hall? Basically a regular grid of flat-topped pillars holding up a ceiling, a feature of ancient Egyptian architecture. More here. Inspiration for this one comes from my holiday in Luxor a couple of years ago.
4 - Tomb of the Under-Bastard
A three-cornered arrangement where the bottom left corner is air-gapped off from the rest of the geomorph. I envisage the long corridor with secret doors at both ends as being a secret outflanking route for dungeon guards of some description.
5 - Fenella's Boudoir
A lot of the geomorphs floating around on the net are very "dense" with paper-thin walls and as much floorspace rammed into 10,000 square feet as possible. This is, I think, a bit more realistic as regards the ratio of solid space to thin air, after all something has to keep the weight of the upper levels up! Bottom corners both lead off to neighbouring geomorphs.
The bottom left dead-end is either a collapse or an unfinished passage.