There is no "best" - the application either works to enable trim or not, Trim Enabler works fine. Another choice is ChameleonSSDOptimizer (Google that for the web site), which also has options to set the noatime flag, set the hibernation mode to zero, and so on. I am using (used) that on my MBP, no issues at all.
Check out this usful thread: https://forums.macrumors.com/threads/1505922/