Go Buick. You will be driving in a tank. A comfy and economical tank at that.
I learned how to drive in my mom's Buick. I did over $1000 worth of damage to it in an incident involving some trees. With the exception of needing a new side mirror, all the damage was cosmetic. We paid someone at a body shop to pound out the dents, and all was good. She still is driving it. The car has had no major issues, very little repair, runs great. I would totally have a Buick, but I hate hate hate the size.
I would totally go for a Mini Cooper - its cute, great gas mileage, easy to park, etc. But I would worry about how it would handle in the Minnesota snow. My Saturn handles all right, but the Buick plows through snow and ice like it doesn't exist.