I went with DAN insurance for a number of reasons:
DAN is a non-profit organization that does a lot of great things for divers. If, in the unfortunate event that I do need to use the insurance, DAN's hotline and their research may well contribute to saving my life.
Their cost is roughly the same as other dive insurance for the same level of coverage, even after adding in the cost of the DAN membership.
PADI insurance brochures boast about the fact that they give a donation to DAN when you buy their insurance. I'd rather get the insurance directly from DAN, so that they get more of the money. PADI's insurance program is through Valencia & Buckley, a private, for-profit insurance company. DAN gets less money this way, and the difference goes to a private insurance corporation.
DAN insurance covers just about anything that happens to you in the water, including infections from cuts that happened while diving or snorkeling.
DAN insurance covers research diving done under the auspices of AAUS (Amer. Academy of Underwater Sciences, I think), which is probably NOT a consideration for most people, but is for me. PADI's insurance does not cover that.
DAN membership has a number of other priviledges besides eligibility for the insurance, which make the membership worth it. Among other things, they include some books on safe diving, and a subscription to their diving magazine.
I don't know about other insurances besides PADI and DAN, but I know that there is every reason to support DAN by buying their membership and insurance package.
One last detail....There is one small way in which PADI's coverage exceed's DAN's. In one of the supplemental insurances (I think it's trip cancellation reimbursement or something travel-related like that) PADI's limit is per trip, while DAN just has a lifetime limit. However, since you are unlikely to even need that coverage, I would say just go with DAN's insurance for all the other reasons, and if you end up needing that supplemental insurance so many times that you reach DAN's lifetime maximum on it (which is pretty unlikely) you can always just switch to PADI's insurance after that.
Sorry this was such a long response. I recently went through the diving insurance search myself, so this was all at the top of my mind. I hope this helps!
Dive safe!
otter-cat
