I've actually been replaying San Andreas lately, after having finished Lost and Damned and Ballad of Gay Tony (on the PC).
Since I'd already legitimately beaten San Andreas once, I decided there would be no shame in using cheats to get through some of the tougher parts of the game that make me want to smash my monitor, Hulk-style. I've managed to easily get through some of the hardest missions with relative ease. Wu Zi Mu, Farewell My Love, and N.O.E. can all easily be beaten by using the "all pedestrians attack you with weapons" cheat. Though the races get a little hairy when you get to main roads, as some pedestrians will try to blow you up. I suck at races anyway. Also, Freefall, where you take the Dodo plane to intercept another plane and free fall to it, I used a handling editor to cut down the top speed of the target plane. AFTER trying it about 10 times and not even coming close. Some people don't like using cheats and normally I don't either, but I don't mind as much if I have already beaten the game without cheating. I just enjoy the game play and don't want to get stuck on an impossible mission, unable to move forward.