I've spent a lot of time on Sheldon's calculator.
I live in the TX hill country and the end of most rides is a 400' climb up steep slopes to get home.
I began with my old Raleigh, wide 5-speed rear, then wide ultra-6 and went to half-steps on the chainrings (46/41) to get rid of cliffs in the gear steps.
This is the second rebuild of my then 35-y-o bike. The 1st rebuild was in '78 around a 27" Zeus/Rigida wheelset, which is still rolling in the photo just below - actually, the rebuild began because the factory splined crank stripped on Austin hills, and the guys at the UT Co-op bike shop had the Mighty Comp (and Zeus hubs) for such-a-deal.
Eventually went to a a cyclotouriste triple crank with half-steps and a little bail-out ring, combined with a 700c wheelset that gave me a wide-7 in the rear.
This was also a cold-set of the rear triangles to 126mm rear axle width.
here's the wide-7 triple for the 3rd rebuild
and the gear chart - didn't have much control on freewheels (the 12-32 7 is a Suntour Winner), so was using the calculator to pick rings on the triple crank
____26__42__46
32- 21.9 35.4 38.8
25- 28.1 45.4 49.7
21- 33.4 54.0 59.1
18- 39.0 63.0 69.0
16- 43.9 70.9 77.6
14- 50.1 81.0 88.7
12- 58.5 94.5 103.5
this worked really well for me, though the 104 inches was really more than I needed, and didn't mind the 70" overlap, because 70 is such a useful cruising gear and having it accessible from either chainring was great (it's also a good common point to make a full-step rear shift). I shift the front on the triple more often than the rear, taking those little steps on rolling hills, and spend a lot of time on either the 18 or 16 in the rear. But it's nice to have those under 30" gears for the steep climbs at the end of a 20 or 30 mile ride.
On the newest bike I built, I tried to duplicate the range and steps of the triple as much as possible in 9-speed compact double - this was a custom cassette, so I could pick everything
and here's that gear chart
____25___42
29- 23.6 39.6
25- 27.3 45.9
21- 32.5 54.6
18- 37.9 63.7
16- 42.7 71.7
15- 45.5 76.5
14- 48.8 82.0
13- 52.5 88.3
12- 56.9 95.6
of course on this bike, I'm almost always on the big ring, and the 9-sp rear is index shift. You can see on the little ring, I have 5 narrow gears taller than the lowest gear on the big ring. I use the little ring for approach and climb, but they're also good gears for off-pavement, and keeps both the chain and RD lifted high out the rocks