First of all, no doubt, GTA V is arguably the best game i have played for the XBOX 360 and it ultimately deserves the 10 score from many reviews. However, i feel that the game could have been improved further in a way that it could be considered the best videogame ever made. Here are my ideas:
1) I feel that the female characters in GTA V have been underutilised. Rockstar should have created a stronger female presence in the game. But instead, we get women who acts like W***** and some annoying characters like Amanda and her daughter. They could have created female gangsters in Franklin's storyline or maybe female characters that issues out tasks to the 3 protagonists in the main storyline.
2) We have famous artists who are featured in the game soundtrack like Rihanna, Dr.Dre, Snoop Dogg, Kendrick Lamar, etc. The songs Rockstar chose were great but it would have been better if these artists had created original songs just for the game. It would have really ramped up the blockbuster feel of the game.
3) It was somewhat of a letdown that very few shops and buildings can be accessible in the game. It would be better if we can visit plenty of shops, buildings and even houses. It would provide more incentives to explore every crook and corner of the map.
4) It would be cool if Rockstar obtains the name licensing rights for the cars and motorcycles for the next GTA game so we get to see names like Porsche,Lambhorgini,Mercedes,Bugatti,Ferrari etc.
5) This idea that i am gonna say now is just a personal issue because of my experience in the game. I wish that not every NPC in the game has to be vulgar. Be it grandmas, old men, teenagers, whenever i accidentally bumped into them while running or walking, or via vehicles in traffic, or normal conversations, they will hurl a series of vulgarities at my character. I am sure in real life, this is not the case.
6) Just like in GTA IV, flying a helicopter can be a pain. Flying a plane now is easy and fun, but flying a helicopter is really complicated and i still have trouble clearing the flight school lessons on the helicopter portions.
7) Chop was really under-utilized in the game. You could only bring him for a walk or teach him new tricks. Rockstar could have built missions around Chop like using him in missions to sniff out drugs or sniff out trails and lead the character to the target etc.
These ideas are my opinions and i am sure some may disagree with these. Feel free to discuss/Add in ideas of your own.