I don't have experience staying at any of the Hyatt's in Chicago (I live there) but I can over advice on location and things to do.

Hyatt Regency on Wacker: Probably the worst location
Hyatt Place River North or Hyatt Magnificent Mile: Good locations for finding lots of things to do and lots of good places to eat/drink.

What kind of spots are you looking for with regards to eating and drinking? Fine dining? Chicago Pizza? Steakhouses? Happy to offer some recommendations if you provide a bit more guidance.

I agree with the previous poster about taking the red line - The Grand stop is convenient to both the Hyatt Place and the Hyatt Magnificent Mile. You will take it to the Addison stop and Wrigley is straight across the street. Keep in mind that the Red Line heading north on game days can be very crowded, especially if it is an evening game and you have rush hour traffic too. It normally takes about 15 minutes to get there on the train from the Grand stop.