From a greed player pov I would want 1 too, as it would help not wasting mana. But really that depends on the availability and demand on the resource, the concept of 'precious' and waste.

If the game can be well balanced independently from the regeneration pace of the resource, I would prefer number 3, or that it regenerates only to half or some fixed percentage of the full capacity. That means I wouldn't be overly dependant on this mechanic, and that the game would have other means of keeping me interested in playing it, or I would have to make up different strategies not involving the resource mechanism.

Any method that results in the player having to run back and forth between the dungeon and town is a bad option. Full stop. Period. A waste of real-time and life.

I prefer my mana to be fully charged at the start of a battle, empty but chargeable, or constantly recharging.

But what's everyone gonna do once there isn't any mana left to find?

Agreed, saves time for everyone to go "whole hog" at the beginning of a fight instead of forcing "conservation" that ends up in wasted real time to get to a regen point.

In theory things like tight resource conservation are a good way to introduce challenge, but when the workaround is to click "rest" or go someplace you CAN click "rest"... it just detracts from the experience, or encourages you to only use cool abilities during a boss fight.

That's just a Chinese myth.

I find the term mana to be sexist, it should be called womana or unisexa.

A few thoughts:

1. Some people have been saying they prefer no mana regen at all; that really isn't the point of this topic. This topic is assuming that mana (or some other resource) regenerates over time and has a cap. Besides, I don't like not having mana regen because it discourages the player from using that resource, and I am of the opinion that resources in games exist to be used; not using it means the player never experiences that aspect of the game. Mana regen makes mages more fun to play in Oblivion than in Arena or Daggerfall, even though Arena/Daggerfall allow for much stronger spells to be cast (and for an exploit where you absorb your own spells, making the resource irrelevant). Having to rest to restore mana also has its issues; sometimes (this is a problem with TES games, for example), the game's definition of "combat" has false positives, preventing you from resting when you should be able to.

2. I think I prefer option 1, as it encourages frequent use of the resource in question. Option 3 does have some interesting implications if the ability controlled by the resource is powerful; use it too much and you lose access to the resource for a while, which means you have to be more careful about using it, while option 1 is better if the resource powers the character's primary ability.

3. Also, for those users mentioning rest or returning to town as means to refill the resource, keep in mind that those options aren't applicable to arbitrary games. In particular, they don't work for Cookie Clicker, which has neither an option to rest nor towns (or any sort of travel, for that matter). Also, it doesn't work for simulation games unless you are simulating people (like in the Sims, for example).

I agree with both.

Some battles at jrpgs are fierce, long and memorable because you ought to spend all the mana (or SP*) and after that use your creativity to still fighting despite having spent all.

* SP: Spirit Points in Atlus games.