Charm Person, lastly, can be used at level 1 and in the middle of combat if needed and contrary to what everyone in this topic has been saying actually DOES allow you to give commands to the charmed person and tell them what to do. Sometimes it requires a paltry charisma check in the case of fighting its own allies, but unless your DM is cheating then it does exactly what the spell says it does and the creature will do what you say so long as you don't order it to smash it's own head into a wall. Beyond that, Charm Person lasts a whopping 1 hour per level, meaning even a level 1 caster using the spell gets far more mileage out of it than anyone with an infinite diplomacy and intimidate bonus. At very very worst Charm Person can be used as a combat trick to remove an enemy from a fight. A level 1 save or suck with an unfavorable saving throw bonus. That only unravels a fight. A better usage by far is to gain control over a crucial NPC and unravel the DMs entire plot. At level 1.
Incorrect, at least as far as Pathfinder is concerned.
Charm Person does "not" allow you give some commands. The DM has the final say so as to what the "charmed" person will do and what is considered "against their nature". There has been a really big misconception with regards to the spell.