My first date was walking downtown and showing him the sites since he never been to Milwaukee before. It was the end of summer so there was a lot going on. We ate at a great Thai buffet for lunch which made it very casual and easy-going. The sites we checked out were a jazz festival, a museum, chilled at the mall for ice-cream and central air, and walked along the lakefront. It was like a 8hr date, but we were hitting it off great and time flew by so fast.
My second date with him was prom night, months later. We went to prom, had a fun time dancing. Then we went bowling with another couple, had pizza and we left to drop my date back home at the hotel. It was a fun night, the second dance I have ever been to in my life.
Since then, other dates we have been on included salsa dancing at a night club, bowling 3 games at a time, dinner and movie hopping, museum exhibits, free days at zoo, hanging out at the lakefront and chill on the beach, taking roadtrips for a day to the Dells, music concerts, comedy shows in Chicago and dinner, and staying home to cook a fancy meal for each other. All were fun, but it helps when your date is fun to just be with.
ETA: museum exhibits are great, but make sure you are comfortable with what the exhibit is. Like we went to the Titanic one, which was fine. We knew the story. However, the Body Worlds exhibit had a few parts that might be taboo to see and talk about on first dates...