According to some people here, since 60 fps is so important to them GTA V must be a pretty bad game? That game drops below even 30 fps al the time.

No. GTA doesn't need fast response. Aiming can be automatic and driving is precise enough. It's like Assassin's creed. But Uncharted is nearly unplayable without auto-aim. Every FPS is bad with 30 FPS (COD rules].

4k resolution is also important, but most of us are taking into account the real world around us.

GTAV on ps3 and 360 was never going to come close to 60fps.

This. Most PC gamers first prioritise their screen's native resolution. It has the biggest impact in terms of visuals.

Usually this means framerates between 35 - 45 for me given my specs. Which most people are perfectly fine with.

Playing games at 720p on my PC to get 60FPS? No thanks.

Exaclty. When I played Half life 2 on my PC. The best compromise for me, (gameplay, immersion, visuals) was 1080p (my native screen) with targeted 30fps and I found this setting without knowing at the time stuff about latency and input lag. I had overall a better experience of the game at 1080p30fps.

The same for the racers I played on PC.

Playing 720p just to gain 17ms response time? No thanks. Too expensive.

Except in competitive games (in a real competition not sunday competition) those 17ms are useless.

60 frames would be more important for me,  especially depending on the genre of game. Platformers and fighting games are most preferred this way.

Example (With stable framerates ok):

GTA V 1080P 30FPS

VS

GTA V 720P 60FPS

Depends on the type of game and how responsive you need to be.

GTAV - 1080p / 30fps

Battlefield 4 - 720p / 60fps

Have you played AC IV? The sailing partially lead me to make this topic. Being able to look out over the waters and spot pixel sized objects in the distance is great. It brought back memories from when I sailed the Caribbean as a pirate...

This is why I dont understand answers like just 60FPS or just 1080p.

it all depends, and with most games I enjoy. 1080p at 30fps is best for my kind of games as long as it's stable.

Although, for PC, mine can handle almost any game on high settings at both.