Question for all of you PADI guys

[seantk]

I am enrolled to take the PADI Open Water Diver class and I plan on taking the PADI Advanced Open Water Diver class also.

I am interested in several of the specialty courses including:

Deep Diver
Enriched Air Diver (nitrox)

What PADI speciality courses have you taken? Are there any other PADI specialty courses that you would recommend? If so, why?

This is something I have wanted to do for sometime - I am looking forward to it!

Thanks

Sean