Now thats a good question! Considering I have went through over 70 cars and trucks and all had some sort of problem/s I realy had to think.
I will go with my 80 Toyota 4X4 pick up. The biggest problem I had with it was easy and cheap (no cost at all) to fix.
It was parked outside and in NYs winters temp could get down to -25 at night. Trying to shift the gears in the manual trans was almost impossible till it warmed up. My free solution to that was parked it in my flat driveway in 3rd gear with the transfer case in neutral.
Go out start the truck and let it run till I finished breakfast and took off for work. Just shift the transfer case back to high 2 wheel and the transmission shifted perfect as it was well warmed up.