2Take1 is widely regarded as the best mod menu for GTA 5 and is at the absolute top-end of the market. It's for the truly elite.
2Take1 also has the best support, with a vast amount of documentation and user-made content such as lua scripts on their website. You can rest assured that 2Take1 will take care of you. There are two versions of the menu, Standard and VIP. See below for a comparison between - both have a fantastic feature set and the same renowned protections and stability that give 2Take1 its reputation.