Sorry if i copied someone but seriously after about a year after gta 4 i raely venture on it and even then i never play the single player whereas i'm always playing san andreas, its just so fun! people have said, its realistic, but that was interesting for about a week and then i just looked and saw a bleak and dry game which ive done everything interesting. But in san andreas we have, Fighter jets, Hovercraft, miniguns, LOADS of melee wepaons, tanks, apache gunships, a desert, a huge forest, myths to discover, and CHEATS! Is it just me or does infiltrating a secret military base (area 69) sound more fun than cheking my emails in the TW@T internet cafe? So don't get me wrong GTA 4 is a great game but San andreas just has so much more to do, and if rockstar were ever to improve it would be to throw in some descent online into a title which expands on san andreas and creates hours more fun.
and if i havent convinced you, just remember one thing, the jumbo jet!