Louisiana-style hot sauces ought to have only three ingredients: Peppers, vinegar, and salt. No thickeners. No preservatives.
Of those you'll find on the shelf at the supermarket, my favorite is Tabasco. It has the fermented fruity complexity and the just-right level of heat. Nothing tastes quite like Tabasco.
Crystal is very good, too. It has the fruity character of Tabasco, but it isn't aged as long, and it lacks the oak-barrel complexity. It is also significantly milder than Tabasco. For this reason, lots of people swear by it, and I understand that. Crystal is very good indeed. In a universe in which Tabasco never happened, Crystal is my #1. In this universe, it is my #2.
Interestingly, I'm a fan of more heat than offered by regular Crystal, so you'd think I'd prefer the hotter flanker. Inexplicably, the hotter flanker has xanthan gum, immediately disqualifying it. Despite this, it is only a step or two hotter and hardly worth the effort. Stick with regular Crystal. You can't go wrong.