I have four Divers here. All legends in their own rights. Pick one and state why.
1) Blancpain Fifty Fathoms 45mm
2) Omega Seamaster Planet Ocean 39.5mm
3) Panerai Pam 682 42mm
4) Rolex Submariner 40mm

 

Out of those choices the fifty fathoms calls to me the most from an aesthetics perspective.

 

Fifty but hold the NATO, ^^^ same reason ^^^

 

yep, the fifty fathoms would get my vote too.

 

Lets add 3 more divers to the list.
5) Breitling Superocean Heritage II 42mm
6) GS Pro Diver SBGH255 46mm
7) IWC Aquatimer 42mm

 

Only because I own an SMPO and have dove with it I'll pick the Omega SMPO.

 

Still the fifty fathoms for me but the Aquatimer is a very close second out of the choices given.

 

Omega Seamaster Planet Ocean 39.5mm for me. Out of the four, it's the most visually appealing to me.

 

Gotta go with the Fifty Fathoms of the first 4/7 listed. The PO, GS and IWC are more advanced modern designs than the other four, but lovely nonetheless - A SM300 and 62MAS reissue could be substituted for more historically direct comparisons.

Two others that aren't mentioned here that are quite nice as well are the Longines Legend Diver (especially in no date form) and the Tudor Black Bay. Oris Diver's 65 is only 100m, but a very nice design as well. Doxa Sub300 and Zodiac Seawolf reissues are great too.

 

Not a close second for me, but second none the less...

 

For me it would be the Planet Ocean 39.5mm, although I've never seen one that size. Have seen the 42mm a couple times and it appears smaller to my eyes so that's probably the size I'd go with. I do love the IWC Aquatimer though, I'd be torn between those two.

The Blancpain FF would be the easy pick for me overall if only it wasn't so large.

 

I'd go with an Omega Seamaster, but larger than the 39.5mm model. Of course I have 7 3/4" wrists so that colors my judgement a bit. Alternately, I'd choose something Sub-ish but different. I've always been a fan of the original Rolex Sea Dweller. 40mm is the very low end of watch sizes for me, but Rolex watches seem to wear a bit larger than they measure. Probably because the bracelets blend so well with the cases.

I coveted the GMT Master BLRO 16710 for decades but talked myself out of it in part because of the size. I was wearing 43mm and 45.5mm Seamasters then. When I finally pulled the trigger on my GMT this year I found that even on my beefy wrists, the 40mm size is not too small at all. My fear that it would look like a nickel strapped to my wrist was completely unfounded. I also learned that my tastes have changed and I don't want the kind of wrist presence in a watch that dominates my wrist and in impossible to ignore. Getting subtle in my old age! My choice for a diver now would be the SD4K.

 

Of the choices listed, I'd have to go for the Planet Ocean - I like the color scheme and the size (I have small wrists). Second choice would be the Grand Seiko - gorgeous watch, from a brand that might be a bit underrated by fans of Swiss watches.

Full disclosure: I have (and love) a Submariner, but I've never been attracted to the Hulk version ... Classic black for me.

 

300MC or 2500 PO 42mm?

Kermit > Hulk

The 6 or 7 suggest is like ignoring the best from Omega and taking the worst from Rolex...

 

Planet Ocean for me, but 43.5mm.

 

I have and dive with the Submariner LV. Wouldn't touch the others. Besides being the best watch for actual diving, it has already appreciated value after four years. Not that I would ever sell it.

 

FF tied with:

 

I don’t dress up my divers so it’s an easy choice. Planet Ocean 39.5 not only has the most advanced movement of them all, but is the most beautiful in my eyes—and with no pretentions of being a dress watch! I’d take the blue one over the black.

Second pick would be the Seiko. Never mind the Pam and the Hulk (I’ll wait for a revised sub with Bruce Banner lugs).

 

Blancpain Fifty Fathoms hands down. It just works at so many levels. I do like the Hulk though...

 

PO. Ticks every box.