Just finished GTA V story mode, and most of the side missions. The story, while goofy, kept me interested, and was WAY better than GTA IV.
One thing I've noticed is that the game has gotten so large and complex, that there are parts of the game that one could completely miss. As an example, you can still do Taxi missions if you want. I mean, at no point in the game does it tell you so, but I needed a "nondescript" getaway car for a mission, and i thought, "Hey! Taxi! That's pretty non-descript" so I called the cab company (something that also isn't mentioned in game), jacked the taxi that showed up, and then the menu for the taxi missions showed up.
Don't get me wrong, it's not some amazing game mode that everyone needs to see, it just leaves me to wonder what else I might have missed in the game.
There were still a few minor annoyances: I stumbled across the flight school while near the airport, and so I did all the flight school missions with Trevor, only to find out later that I needed to do them all again with Michael. Would have been nice to get a heads up on that. Or leave it locked or something until that mission.
Also, no spoilers, but you can play the stock market in game, and you get some pretty solid tips throughout side missions. In retrospect, I wish I had completed every other mission first, so I had LOADS of cash to invest when I got those tips.
I also thought the "random bystander" missions were interesting. Someone would get robbed or something, and you could choose whether or not to help them. What was neat was that there was no moral certainty to your choice. Many times, you could kill the robber, and just take the money and run, with no consequence. Occasionally, when I would return the stolen stuff, I'd get a minor portion back as a reward, or an email with a little reward. It was a natural feeling mechanic where you *might* get rewarded, and might not, and were left to your own devices.
I'm totally done with full game collection missions. Maybe that tickles someone else's fancy, but not mine. I liked the mechanic in ACII where picking up the hidden stuff would unlock weapons, but the "collect for the sake of collecting," no TY.
Haven't touched online yet.
Overall, I really enjoyed the experience, story, characters, etc.