Scribe Ineti
Explorer
I don't know if it's the best, but I've been really happy with the LOTR RPG magic system. Subtle magic, no spell slots, points, or memorization required. If a spellcaster knows a spell, he or she can cast it, whenever.
And casting spells could result in the spellcaster getting fatigued. I like.
And casting spells could result in the spellcaster getting fatigued. I like.