I would love to pick rogue as that's the class I always play in video games and RPGs, though I suspect I'd rather be the kind of rogue who picks locks and disarms traps rather than the typical RPG backstab monster.
But in truth, I'm better suited to being a mage so I picked that. I'm not particularly strong or agile, knowledge and learning has always been more my thing so I think I'd probably live longer as a mage than as any other class.
Plus, the way you're phrased magic makes it incredibly versatile and powerful. With that kind of power you could basically do anything, including making yourself immortal and invincible if you so wished. I'd suggest maybe tweak what "magic" means in this bargain so it's something more on the level that could be reached by a really skilled warrior or rogue.