The "Big Three" are TravelGuard, Access America and CSA. I sell both TravelGuard and CSA and have used all three. Right now for divers, especially if you have DAN insurance, my current favorite is CSA Comfort policy. Covers pre-existing conditions as long as it is purchased prior to final payment for your trip. Good coverage for most issues.
If you want extremely comprehensive coverage, TravelGuard Cruise, Tour and Travel is primary and extensive. But more than 99% of people need. I tend to view it as overkill.
Be careful of using homeowner's insurance to cover items. Many areas of the country if you have 2 claims in 3 years (even if neither of them are loss issues with your house, or are very minor), you are put into a high risk pool and are almost uninsurable. I'm unwilling to risk the coverage of my house for that. DEPP covers my electronics.
Let me know if you have other questions.