What are some of the weapons that don't require a charge but still have an effect? I mean like Mehrunes Razor, Silver weapons, windshear, that one dagger that gives +25% crit... etc... And is there a list anywhere?

Ebony Blade and Wuuthrad

I don't know of a list organized by 'chargeless enchantments'. you might just have to go to uesp unique items and specialty gear. not much help, if you already know the names you can search by name and get location on each article one at a time.

Dawnguard weapons.

The Poacher's Axe probably, as well. You can see the charge bar iirc.

Though the Dawnguard Rune Ax supposedly resets its charge after you temper with it.

The axe is amazing.

Horksbane

Actually, Windshear has a charge. I've ran out of charges with it before... Unless they changed it in a patch.

Oh and Keening.