In Kindergarten & 1st I rode a late 70's/early 80's Carpenter, looked like a squared-up GM fishbowl, drafty, roof leaked in about six places, ineffective heat, weak body flexed in every curve.
From 2nd grade onward it was a '68 Gillig w/2 cycle Detroit power & 6 spd. Allison automatic. Built like a tank, seldom broke down, great heaters. Grade school students weren't allowed to sit in the six rearmost seats because of the noise level generated by the "Screamin' D". Twice every day we crawled up West Bay Marina Hill in second gear with the "Leaky D" going full tilt at what I imagine were 100+ decibels. Most of the bus drivers preferred the Gilligs to the late-model junk. The district even had one with an offset aisle that sat three on one side & one on the other. I think it was a '66.
Field trip buses were front-engined IH diesels with [censored] Carpenteresque bodies.
The last resort spare was a front-engined IH gasser w/auto trans that smelled of cigar smoke. My friends and I speculated that it also served as the mechanics' break room.
Around the time I started High School the district renewed the fleet with rear-engined Thomas-builts. Air-conditioned, insulated, air-ride equipped, quiet, maneuverable.
I never rode in a Crown. Tacoma School District had them. I suspect they would be my favorite if it had been in the cards. The Gilligs were by far my favorites for one good reason: they were interesting.