If there is any other franchise i could say,then its definetly Metroid. Nintendo really nailed it making the series consistent within its series (for example,events of Other M are told in Fusion,and Super Metroid recaps the events of Metroid 1 & 2) and to have a huge player fanbase. The games make you feel like your exploring planets un-known to humanity,finding items to help you survive and complete your main mission. Boss Fights allow you to make strategies to use; and if you fail with one of those,you come up with a new one to try out.
The series has also been commercialy and critically successful (with a few mediocre entries).By the time of the latest entry in the series, which is Metroid Prime Remastered, sales of the previous games on Nintendo E-Shop have been extremely higher since the release of Metroid Dread,and they still countinue to rise up.
My favorite games by far are the GBA Titles (Zero Mission and Fusion), Super Metroid, Metroid Dread and AM2R. Those games are the peak of the franchise,and it will remain that way.