By the time I was almost finished playing through GTA III I was a God damn cheating master. I could input like 5 of those bitches in 15 seconds from memory.They great thing about those codes was you could put in the sequence reeeaaallly quickly once you did it enough times and memorized them. I could enter some of the ones that ended in left+down+right+up (x2) in less than a second since all you had to do on the d-pad was makes circular motion with your thumb lol.
Never cheated in any of the games after that, though. Pretty much got my sandbox mayhem fill from GTA III. I rather linearly played through the narrative of Vice City and never even finished San Andreas.
I also played GTA IV fairly linearly. I think I finished it in less than 20 hours.
I played so much GTA III in high school that I completely burnt myself out on experimenting in sandbox games for pretty much ever.