One of my notchs has:
3.73's, AOD w/shift kit & +400 stall.
A lot depends on your engine build ... what rpms is it built for.
I have a mild street build ...
With my taller Automatic gearing (compared to my T5 car) I'd prefer the acceleration of 4.10s playing the stoplight-to-stoplight game.
However, on the highway with 3.73's it consumes more fuel than desired and it isn't a long-drive to the beach car although it's nice enough to look like one
... for this I would prefer 3.55's or maybe 3.27's.
All in all, I think the perfect gear is a 3.55 for a daily driver/cruiser set-up ... if all you do is run at the track, then by all means go with 4.10's or 4.56's
The difference between 3.73's and 3.55's is about 200rpms at cruising speeds.
When I drive my AOD car (stock tire height) it always feels between gears when cruising with the 3.73's ... not fast enough for OD, but a little too fast for D:
60-65 on the highway is about 2100-2200 rpms ...
Although I do like to cremepuff my Stangs as much as possible ..that way they're good and reliable for the open roads