In Dungeons and Dragons Online, I always loved the concept of True Reincarnation. It gave you access to more powerful builds, allowed you to experience many different playstyles on one character so as not to necessitate rerolling, and greatly extended the life of the game.
Incase you don't know what True Reincarnation is, I'll explain it.
True Reincarnation in DDO essentially rerolls your current character and starts it back at level one, but with all the same gear and gold stored in a separate bank granted upon reincarnation that you can withdraw from at any time. Reincarnating this way starts your character at level 1 with a potentially new race and class and a more potent build (DDO gives stat points upon character creation, you can be a 28- (free), 32- (premium), 34- (2nd life), or 36-points (3rd life) build) as well as a unique feat(s) determined by your previous lives.
Then proceeds the grind back to max level and potentially another life. For example, a DK past life could give a 1-2% bonus to fire damage per stack of that life up to say 3 while a Templar past life could be 1-2% healing done and/or 1-2% magic damage.
In addition DDO also has a completionist feat that is obtained for having at least 1 life per class that gives a +2 bonus to ALL stats and skills. In ESO, this could translate to 1-2% spell damage, weapon damage, resources, and spell/weapon crit. Not enough to give a substantial enough boost to break the game but enough to reward those who put in the effort of playing all of the classes.
Valrien Dravic -- Level 50 Dunmeri Sorcerer (EP)
Garahel Dravic -- Level 50 Bosmeri Nightblade (EP)
Tamriel Unlimited was a mistake. One Tamriel was a bigger mistake