Tony Hawk's American Wasteland (PC). Story wise, I'm about to unlock the ability to ahem acquire parts for the Skate Ranch. However, screw that noise. I'm here to try and break open the speedrun route. I figured if I can glitch my way into Casino, that should, in theory, allow me to skip about 90% of the story (in theory). So far, I've glitched into Downtown and East L.A. Getting into the little area right before the tunnel leading to Casino is proving to be next to impossible. However, if I can actually get to that little area, then glitching into the tunnel leading to Casino will be a cakewalk.
On a side note, I've found a way to glitch my way into Santa Montica (well, kinda, seeing as the final door is closed, but I can get to the tunnel). So, outside of Casino, that just leaves glitching into Vans Park (possibility at 10% right now) and Oil Rig (impossible without Set Restart/Go To Restart in story mode).