Inspired by this list from Drax. Franchises where the first game is (arguably) the best one, whether because the rest of the franchise just doesn't compare to the first entry, or all the other games are just as good and thus it becomes debatable on which one is the best.

Rules (so far):
1 - The franchise must have atleast three games (so no Hotline Miami for example), and no expandalones allowed either (such as Half Life 2 Episode 1/2)
2 - Sub-franchises are taken into account (such as Mega Man X or Star Wars Jedi Knight) but anything such as nuDoom is disregarded.

Suggestions are more than allowed.