These are SSI course names, though I'm sure every agency has equivalents. For SSI, Stress and rescue is a requirement for Master Diver.
The question was geared specifically to PADI. I've already done Rescue Diver ( although I wouldn't mind sitting in it again ). My typical boat dive in Lake Travis is deep, cold, low vis search and recovery (loot from party boats) activities. Let's see...
Altitude Diver - perhaps, not really on my radar
Fish Ident - that could be fun if I ever see blue water again. Until then there's bass, carp, cat fish..... any questions?
Boat Diver - Um... enough said ( I do miss Blackbeards... )
Photo/Dig Photo/Video ectera.... ya, not my thing. Too much $$$
DPV - That'd be fun but $$$ and would be part of tech training for me (Um, SeaDoo's don't count )
Drift diver - Um, I miss Cozumel too..
Dry Suit - Perhaps. As long as they don't try to convince me to use my drysuit for buoyancy control. I think I can learn this from a mentor
Oxygen Provider - perhaps
Equipment Specialist - I'd rather take a Hog regulator tech class
Nitrox - sure, done
Multilevel diver - really?
Nighy diver - pretty much every day dive is a night dive here
PPB - I'd rather take a DIR-F
I guess my point is even if I wanted to waste $500 on four more classes, I just don't see anything worth taking.