I have a 3x9 on 700C wheels: 44/32/22 triple on the front, which works best for me with 11-28 cassette, which gives me close enough gear spacing and all the range I need. When cruising on road, I'm usually in 32/11, 44/14 or 44/13 and doing 25-33 kph at around 70-75rpm. On forest trails it's usually between 32/21 to 32/12. The smallest chainring is only for very steep climbs, loose sand or other soft surfaces.
I recently did draft a truck and spun out at 63 kph, which is around 120 rpm. Of course, I can only dream of going that fast on a flat road without drafting, so my gears are more than enough for me.