Well i am at a corssroad, whichone do you think is best? I would personally guess regen

What for? In combat take fortify stamina. While exploring go for regen

Or, if you're epic, both.

Well i use the same boots for exploring and fighting, i use my ohter enchant for one handed damage.

If you're running out of stamina before most of your typical fights end, you'd probably want to fortify your stamina. But only if the amount you're adding to the pool allows you to finish the fights before running out of gas. If your fights go well beyond that point, I'd focus more on stamina regeneration. So, you have to anolyze how you fight. If you can pounce your opponents and lay waste to the crowd of them in under 10 seconds, then regen is probably going to be pretty useless since it won't really have time to come into play.

Whether you have 300 stamina or 100 stamina. When you run out of gas and hit 0 stamina you regain it slowly at the same rate. Making any extra stamina become wasted points.

So the best option is to go for pure stamina regen which is basically unlimited stamina after a certain point.

I just ignored both and made a weapon of absorb stamina + soul trap, With asura's star I never run out of Stamina at all now and am capable of doing constant power attacks, no matter how many mobs or npcs are around.

Before you can make a weapon like that, just get asura's star and use a main weapon with absorb stamina and an iron dagger of soul trap for ~X seconds to apply the effect, alternatively use the spell.

If you have a stamina pool of 200 and can wrap most fights up in ~10 seconds with a pool of 250, then boosting your stamina would be wiser than boosting your stamina regen (as regen is really not going to get to come into play until after the fight is over). It really depends on how much stamina you use when fighting, and everyone fights differently.

You consume the same amount of stamina with each attack, not the same rate, if I'm not mistaken.

The same goes with sprinting. More stamina allows you to sprint longer