If the PS4 and Xbox One versions of the game were a step up from the PS3 and Xbox 360 editions, then consider the PC version a slight step above them. Provided you can run it at its higher settings, anyway.
The game helpfully includes its own benchmark test, which aside from helping you test out your settings also does a good job of showcasing most of what GTA V has to offer visually. There are some floating shots to start off, which run through lighting and weather effects, before the test closes out with a jet flyover and a driving sequence.
Nvidia users have a special driver just for the game; it seems to do this weird thing (I've played the game both before and after installing it) where it tries to lock your framerate at either 60fps or 30fps depending on performance. Prior to this, it would swing wildly, which looked a lot worse.
For some more personal footage, I also captured some stuff from the ground floor. The cars look especially nice.