Looking for ideas. What are the best activities I could do together with my pregnant wife?

Agree that antenatal classes and couple prenatal pilates/yoga classes are great options. How far along is your wife? If she is still in her second trimester, you can also consider a babymoon! Second trimester is the safest period for a mother-to-be to travel and she has also likely gotten over the physical discomforts often associated with the first trimester. Other things you can consider are shopping and getting the nursery room ready! Simple meetups with friends will also be good. Movie dates may sound simple, but after the baby comes, you may not have the luxury of time to step into a theater for a 2-hour movie. Have fun! ;p