I've tried a bunch of saddles and so far the contemporary Selle Italia narrow racing style saddle seems to suit me best -- flat, solid top, no upward flares, curves or perineum relief cutouts. With the right shorts (and pedaling effort) it's fine for up to 60 miles or so. My longest ride this year, 105 miles on that saddle, included a long lunch break around the 60 mile mark, so it wasn't a continuous century ride.
I started with the low priced Selle Italia SLS Kit Carbonio when it was discontinued and heavily discounted a couple of years ago. Selle Italia does that pretty often so I'll probably get another with the same dimensions, although they change model designations too often to keep up with. But if you wait awhile their $200+ MSRP saddles will sell for under $100.
Unfortunately the slightly wider, more padded Selle Italia Q-Bik didn't work out for me. It's just enough different to be uncomfortable after 20 miles or so.
An old and nearly worn out Selle San Marco with a split rear but otherwise similar to the Selle Italia has been pretty comfortable on my hybrid.
I'm trying a Bontrager Ajna woman's saddle with generous perineum relief cutout. It's a little wider and shorter, but the main problem is the wider cutout leaves less saddle actually supporting my sitdown area. So after an hour or so I can feel the saddle digging in. It's better with thicker pads, like the Coomax pads used by Przewalski shorts and bibs.
So I'll probably stick with the solid top saddles, flat or nearly so without significant upward flare at the rear, and no hammock type design.