Idea:
Restrictions breed creativeness. Thus a random color combination and commander is reasonably chosen. While the color combination are equally likely, the commander is based on the amount of decks available on edhrec for each commander.

To keep this casual, the following restrictions apply:
-No nonland tutors
-No extra turns
-No land destruction
-No infinite combos
-No alternate win / lose conditions
-No taking other people's turns (mindslaving)
-No permanent taking control of other people's permanents (That includes vedalken shackles since they may remain tapped indefinitely, Treasure Nabber / Mass Mutiny, since they'll be returned shortly)
-Budget of 100 EUR of cardvalue

I call this set of restrictions: Poor Timmy!

Choosing the commander (in python3):

import random
import itertools
print(random.choice(sum([list(itertools.combinations(list('wubrg'),i)) for i in range(1,6)], [])))

then go to edhrec, sum the amount of decks for that combination, random.randint(1,amount_of_decks)

and decrement that number for each deck until it is <= 0, pick that commander