This is a great topic, BTW.
I have some pretty strong opinions here.
The speedmaster reduced and portofino are great pieces, but both too small IMHO and the Standard Bond Style SMP is also great piece, but there are just too many of them out there for me. I like the electric blue SMP, though. The superocean confuses me (Breitling Diver?), but I think it's beautiful. I love the Speedy Pro, Vintage Seamaster (beware of fakes), Nomos, Kobold ideas.
I would absolutely not buy new. For under $1500, I would recommend surfing TZ, WN, watchseller, bernard, and the other standard online venues and you will find some great buys.
The following are in no particular order, just a shopping list of some I like:
Standard fare: Speedmaster Professional, Aquaterra Co Ax 41mm, Seamaster GMT, Chronomat Blackbird, IWC GST Chrono...
A few you won't see everyday: Zenith Port Royal Dual Time, Dubey and Schaldenbrand Aerodyne Duo, Kobold Seal, Sinn U1, Sinn 856 GMT, Nomos Tangente Date Beta Sapphire Back, Girard Perregaux Traveler II, Meistersinger Single Hand...
A few vintage pieces (be VERY careful for authenticity): Vintage Heuer Montreal, Vintage Seamaster, Vintage Datejust...
You should come up with a simple informal decision matrix:
Dress, Sport
Braclet, Strap
> or < 39mm
Water resistance
Complications
Price of long term maintenance
Common or more unique
Vintage or modern
Wear everyday or seldom
Horological significance
Box and papers important or not
How long do you want to keep and wear it
This is likely a piece you will keep for many years. As strange as this sounds, I would pick something rather boring as compared to an LV Sub, Crazy Hours, PAMs, etc... (that's why I like our reps - to try these pieces, my gens are much more conservative). It should withstand fads and changes in taste.
I would shoot for something on a bracelet, equally dress as sport, 100m+ WR, between 39 - 42mm, modern, with box and papers - no complications other than a sweep second and a date. Some horolog. significance. Simple Dial. Timeless.
Perhaps this.
Take your time and have fun hunting; there are so many great pieces at your price point.
Cheers,
Spaghettiman