Both my wife (no pics) and I got certified in 2005 as open water, Divemaster & Instructor in 2008.
Dives:
US: Texas - Blue Lagoon, Lake Travis, Lake 288, Florida - off the Coast of Naples/Marco, Key Largo, Key West (Vandenberg is a great artificial reef - on a normal year I dive it 4-5 times), Maui - best was hammer head dive off Molokai
Canada - Lake of the Woods, Ontario - not for pleasure was resetting lines that broke off anchor
Caribbean - Jamaica - Negril (1st dive and many since), Barbados, Bahamas, Antigua (heard whales during dive), BVI, Cozumel - if you dive there do a cenote dive on the last day great dive and rinses your gear in fresh water.
Best Dive - Hammerheads in Maui
Scariest dive - regulator popped and free flowed at 80 feet on descent to Vandenberg, buddy (Mrs Oglilthorpe) was close and grabbed Octo ascended safely. It was incredible how the training kicked in. Went through 2800 psi air in 4 minutes on my tank. Went up for short surface interval, went back on different reg.
Easiest Diving - Negril - great viz, little current, decent reefs
Regarding online certification it just takes the place of the classroom instruction, you still need 4 dives over 2 days with an instructor for certification, at least with PADI - I would recommend online to anyone interested. Also, I would suggest getting certified at a resort that you can borrow equipment from, otherwise the dive shop you work with will make you buy Mask, Fins, Snorkel, Weight Belt and sometime weight that will cost minimum $250. If you don't like diving you are stuck with the equipment.