This is so far the best game to grace my ps2 (with the exeption of destroy all humans, of course.)
In San Andreas, you will play the role of a young man named Carl Johnson, "CJ", whose mother was murdered, and you have to find the murderer, by completing mission after mission. But you have the help of you three gangster friends, "Big Smoke", "Ryder", and "Sweet" (CJ's brother). At least one of these men will accompany you on a lot of your beginning missions, to kind of help you with getting the feel of the game. Missions are great and original. They range from shoot 'em' ups to stealth to bosses to car chases and drive-bys. And every single one is as fun as the last.
One of the many new features in San Andreas is the ability to swim (FINALLY!!). Swimming is probably the best new part of San Andreas. There are also plenty of new cars, boats, planes, jets, and other vehicles. Another new feature added to the game is the ability to climb over and on top of things, such as fences, walls, and dumpsters. Since San Andreas is largely focused on gangs, you will be able to have gang wars, and take over territory, which is another new thing. A humongous arsenal of new weapons is availiable and some aren't obtainable by using the old, reliable cheat codes. The map is HUGE. About ten times the size of Vice City.
Graphics in SA could be muich better, but for everything they put in the game, they did a hell of a good job. Sound is better than Vice City, and the radio is amazing. Theres a station for every type of music, and some have two. The music is incredible, and the talk shows are hilarious.
Grand Theft Auto: San Andreas is an incredible achievement in games, and should be given a chance by everyone.