If it's summer, rent a car. Don't do the rail pass (see the thread I just happened to create). While driving anywhere in Jpn is nerve-wrecking for me (due to driving on the wrong wide, if you're coming from Amercia), it still beats relying on JR Hokkaido and buses. There are many great places in Hokkaido that are not convenient to get to unless you have a car.

When you say you're both active and everything looks great, what activities do you and what looks great?

For first-timer and you just want to limit yourself to like 4-hour radius of Sapporo, definitely at least a couple days in Sapporo (shopping, eating), ski jump place (loved it personally), Shiroikoibito chocholate factory (1-2 hrs), few hours to max 1 day in Otaru (not that interesting imo), Asahiyama Zoo if you fancy animals, Shakotan Peninsula, Furano-Biei corridor for flower fields and farm restaurants/shops and other agro-tourism, Asahidake Ropeway, Souunkyou, Noboribetsu or Jozankei for onsen, Niseko for river sports and other physical activities. Hakodate is a bit out of the way, but it does have a great touristy seafood market and some people love it there. If you want to spread your wings, you could head out to Tokachi (some more agri-tourism stuff) and even Kushiro and Shiretoko.