What areas of Chicago must I avoid?

Have to careful EVERYWHERE you go in the city. There's no way to answer your question since you do not state what your looking for. If you want to do some neighborhood and hit a few pubs, restaurants and shop storefront places...a few I can think of are the Armitage/Sheffield area, Lincoln Square is nice as well.... and further north on Lincoln between Montrose and Grace....Andersonville is another place to walk and grab a cup of joe and interesting shops to investigate....it's funny because you can go 3-4-5 blocks off these areas and find yourself in a "different" area....AKA sketchy

Depends on whether your a Cubs or White Sox fan.

If you whites sox fan avoid the North side of Chicago and if a Cubs avoid the South side.

You could always just say, Da' Bears, and you be fine anywhere.

englewood on the near south side; all stupidity on the corners.

the north side is to be avoided if you drive a car, because there is no where to park & you'll get towed in 30 seconds.

don't go anywhere unfamiliar at night.

Staying under the lake for to long, it will be hard to breath and cold

West side and the south side

south chicago i would avoid