Personally I would stay away from the nitrox if there is such a dive for the reasons mentioned above. If you want to take the nitrox specialty later then you will actually be able to use it. If I remember correctly it's just a few hours of instruction and playing around with your dive computer on the same night and is therefor pretty inexpensive. It just seems like a waste of a dive. I would suggest:
Deep
Underwater Navigation
Night
Search and recovery
Peak Bouyancy
Depending on where you are taking your class and where you intend to dive, Drift might be another but I don't see one learning as much from the dive but drift dives are definitely fun. I think the dives above will give you the most valuable new experiences and show you more things to practice in the future to work on.
Deep
Underwater Navigation
Night
Search and recovery
Peak Bouyancy
Depending on where you are taking your class and where you intend to dive, Drift might be another but I don't see one learning as much from the dive but drift dives are definitely fun. I think the dives above will give you the most valuable new experiences and show you more things to practice in the future to work on.