Being a woman I can naturally be picky here is my 2 cents hope it helps.
The twin ports can be fun or hell pending on where you stay -a lot of the places are rat holes and sleeping in the car at the McDonalds parking lot or calling up the Grandparents to crash on the couch has more appeal. But there are 2 places I have stayed at and recommend.
The Inn on lake superior in Canal Park or Barker’s Island Inn they are clean and safe.
Here is a link to some deals Spirit Mountain has with local hotels + hotel info.
http://www.spiritmt.com/lodging.aspx
Duluth has a Pizza Luce and they have live music.
http://www.pizzaluce.com/enterlink.html
Another local place is Sammy's Pizza; I grew up loving this place. When I am in town I go to the one in Superior on Tower Ave. it is kind of a sad Italian decor with a bar but the food is fab. and so is the bar tenders drinks. The pizza is a very good thin crust style and they don't skimp on the toppings they are usually packed or backed up with take out orders so plan on 20-30min on the pizza -2 people, get the large it goes fast.
If you want a semi fancy place to go for dinner but affordable ($9-$20) go to the Hammond Bar & Steak House on N.5TH St in Superior. It has a small menu but huge portions with lots of sides included and they do have fish that is fab too.