What is the best 3rd person crosshair out there? Ive been searching for a while, but they all seems to be unaccurate or somehow buggy.

Suggestions?

It's an option in darnified UI. I'd say use that.

If you want it in 3rd person, and have DarN UI installed, you can either turn it on every time you load your save in the settings menu(which is better if you don't use it often), or you can make it so it always is on in the hudmainmenu_config.xml file under data\menus\prefabs\darn(right click on it and pick edit). It's one of the first things you'll see, assuming you don't have wordwrap on.

Test this mod, it add a fake third person view with crosshair on first person view. I love it. Here is the link http://www.tesnexus.com/downloads/file.php?id=29942
Hope this helps