I ride old bikes and I like triples. For serious climbs, I like a 28 running on a 24 or a 28. For my local rides a 38/24 works fine but there is nothing steeper than a 10% grade locally and those climbs aren't too long.
One of the reasons I like fixing up old French bikes is that many of the stronglight cranks that came stock on those bikes let you run smaller chain rings, simplex RDs can generally handle larger freewheels, and there is generally clearance for a 28 or even a 32c tire. So some of the design choices we see on modern bikes have been around for a while in some fashion or other (and even before the mountain bike).
This is my 1982 Peugeot PXN 10: 50/38 rings, 13-28 6 speed freewheel, and 28c tires. The rear derailleur that came stock on the bike can handle up to 30 teeth.
