The most profitable bets for me in each session are straight, moneyline and totals. Parlays are also profitable but I only do them when odds for moneyline and handicaps are too low. I try to stay away from them because something unfortunate happens most of the time and I always lose by one leg.
Which of these earn me the most money? Isn't the question irrelevant?
These types of bet do have different odds offer so it depends on the odds. Even I like to bet on Moneyline but the odds are not interesting then I will switch to another one and so on.
Technically, the parlay will give the most rewards but it doesn't mean that's the most type of bet where anyone can win most.
It's the same as the title above but it sounds misleading because the term payout could also mean like winning a single bet or just winning overall but since OP mentioned each type of bet it's easy to know what he/she meant with the term.