I was actually going to post about specialties in the DEMA thread, but I thought posting here would be more appropriate.
Specialties have become a double-edged sword in diver training. One one hand, a student, even a career-professional with over 100 C-cards like myself, can learn something in any course. The problem is ascertaining the value one gets from investing time and money in a specialty course. Too many specialties may, in fact, be one of the things that turns prospective students away from diving because the advancement toward being a "fully trained" diver can be confusing.
Specialties that obfuscate a clear progression of valuable specialty training may turn a diver away from specialties that may be important to a diver's growth and poorly run specialties can do the same.
The saying, "It's the instructor, not the agency, that makes the difference," is most critically applied to specialty training.
Perhaps the silliest PADI Specialty was Underwater Basket Weaving. Yes, it did exist! But, put that specialty in the hands of the right instructor and the course could very well ask students to maintain critical buoyancy and trim, while performing emergency problem-solving while a team is task-loaded with weaving a basket throughout all drills.
Perhaps the OP should have asked, "What is the best and worst sounding PADI specialties given their titles?"
As someone who is deeply concerned about the decline of our sport, I would say that the best PADI specialties are those that sound valuable and dignified and those that promote the importance of continuing education.
The worst PADI specialties are those that would make a diver somehow feel that continuing education lacks value, merit and is not worth the investment of time and money.
In reality, the specialty that serves to educate and keeps a diver moving ahead in personal or professional goals is the best, no matter the title. Diving also needs to be FUN as well as educational. Some of the most ridiculous sounding specialties created to enhance fun may also be hidden gems of knowledge because the instructors may have been excellent.
From personal knowledge, the Scuba Connection's "PADI Team Success" specialty is one that enhances diving both in title and in merit.
Some specialties that sound suspicious, but may be hidden gems, and (quoting from padiinstructorinfo.com) are PADI's:
Underwater model (mentioned)
Underwater Habitat Specialist (I personally took this one. My only PADI C-card!)
Underwater Pilot
Helicopter Diver
Lava Tube Diver
Loch Diver
Submarine Diver
Available Light Underwater Photo
Zen Diver (mentioned)
Backpack propulsion
Golf Ball Diver (mentioned)
Spacesuit Diver
Sinkhole Diver
Future Perfect Diver
Magnetometer Diver
Millennium Diver
Railroad Yard Diver
Sand Pit Diving
Underwater Game Player
Underwater Hockey
Underwater Wedding (mentioned)
Y2K Scuba Historian
. . . and the inevitable
Underwater Basket Weaving (mentioned above)
Here are a few that I’m not sure Project AWARE Foundation knows about:
Delicacies of the Sea
Edible Marine Life Diver
Gourmet Diver
Seafood Gourmet Cook
But, as we know, one can't always judge books by their covers nor courses by their titles.