The first Stuntman takes the cake for me, there. It was common to fail a challenge repeatedly, sometimes only 5-10 seconds into the course, and it had to reload the entire level on each and every retry, which could sometimes take upwards of a minute.
I think I spent at least 2 of the 3 hours I tried to actually play that game just staring at loading screens. Suffice it to say, I neither got very far or was interested in even trying to make it to the end....