I like to do it in FFVII, where i impose different rules each replay. One replay was like each character could only use materia of a specific color (E.g. purple for Cloud, green fir Tifa and yellow for Red XIII), or only one damage dealer, only one healer and one tank (Cloud being the only that can use attack skills or purchase new weapons, Tifa only with healing and buff materias and Red XIII doing nothing more than having cover and lots of hp pluses). It's always fun af and i just can't play the vanilla experience anymore.
Also, don't have patience for nuzlockes but i like to do my lazy Pokémon run, where i will have only 6 Pokés the entire game (Plus hm slaves if needed, but won't use in battle). To make things fun, i'll catch the number of Pokémon equal to the number of creatures used in the last gym, so i catch the 6th one only in the victory road most of the time. I not only avoid having more pokés than the current gym leader, but i also manage to beat the game with the least grind possible, since i have like only 3 or 4 pokés halfway in the game.
