GTA is the first game that you could walk freely and ride cars where ever you want.After San Andreas,they broke the ice
First you start of as a guy only whearing a A-shirt and a jeans, with no respect, 0 ability, and 0 driving skills.But later in the game your gonna costumize him with chains, and jakets, wathes,helmets(even you could find underwear).
If you hop on a bike, you have a big shance to fall at really low speed by hitting at a wall, but if you keep riding it for some time, and practis, you could even bunny hop a hole fens.
San Andreas is a really fun game that lets you play as a man that has got a hole adventure on its way, and that's what makes it fun.
(And dont forget co-op play, then the fun really begins)