In no order just off the top of my head. I took a bit of pride in my high milage vehicles so I remember what they had when sold or parked.
90 suburban 266k at least 1 tranny ran like a top, sold to my baby bro
94 GMC 2500 312k 3 trannys smoked and very weak, in the back 40
97 GMC 1500 234k runs like a top no oil leaks or burning current DD
91 s10 2wd 253k engine swap 314k when i sold it
85 jeep cherokee 2.8 320k all original NO POWER lots of smoke when I sold it
1984 K5 6.2 426k when I sold it I swapped in a sm465 and 3/4t axles just after I bought it
87 ford f250 6.9 diesel 360k no power, smoked

leaked and burnt oil faster than a siv. God I hated that truck.
I have had LOTS of vehicles with high milage but theres 2 I didnt own that take the cake.
my grandpas 74 dodge 3/4t 2wd has 514k still runs but dont hardly every get used
And my dads uncle had a (87 bodystyle) ford f350 with the first gen powerstroke it had over 600k on it. He used it to haul horses all over the united states.
Now most of these had high milage when I got them. theres only 3 that I am sure was original. the 97 I bought from my work have all the receips on services and repairs. It was drove by a little old man that did maintainance at the disposal pits. the 85 cherokee had 26k on it when my mother bought it when she gave it to me it had 190k. And the 94 GMC 2500 my dad bought with 44k and gave it to me at 299k. I babied that truck just to get as many miles as I could out of it. It actualy still runs but smokes bad and wont go faster than about 30mph.
Balzer