I have yet to play GTA V, I've heard it's amazing though!
My favorite GTA game that I've played would have to be GTA: San Andreas. Despite it's outdated graphics, it's still one of the best games I've ever played. It's great story line, gangster theme, cool side missions, and more.
What's your favorite GTA game?

My favorite is GTA Vice City, even though the graphics are outdated I really enjoyed the fun missions and going into the big mall and causing chaos

My favorite Grand Theft Auto game is probably GTA V due to all the heists and side-missions. San Andreas is second due to the casino, I always lost my money, but it was fun.

I have not played the game. I don't think it is suitable.

GTA: San Andreas..

I have played all GTA games and I must say that my favorite is GTA Vice City. As Mr_Lamont said, the graphics are outdated and démodé, but the whole plot, the story line and the missions are very interesting. San Andreas is another perfect game which I used to play daily. I have recently purchased the latest game of Rockstar, GTA V, which is very impressive. It has so many innovative features and new missions which I totally adore. However, I don't really like the three characters thing. It is so weird, isn't it? In addition, I think that GTA V Multiplayer Mode is very complicated. I don't even know what I am supposed to do.