single player will always be fun to fuck around on. I fucked around on san andreas for like 8 years and didn't get bored of it and I don't see myself getting bored any time soon, but I find myself losing interest in the online. it's really repetitive, and hard to earn money and level up. and the cops are ALWAYS on your ass for something it seems. it's just bullshit that you can only drive around in your own car and it takes days of playing time to get good weapons. plus there are always dickholes just looking to ruin your day, and when they kill you, you lose a good fraction of your money. i'm not sure what percentage you lose every time you die, but if you're in the 40-50k area you lose 1-2k every time you die and it's not always easy to earn back (most jobs give around $1000-$5000, more for winning races)
definitely worth buying though.
and where the fuck is my stimulus package