Any good recommendations for a day in Vancouver or excursions in other stops for ages 8-75?
Without knowing much about your family's specific interests, my advice will be overly generic. The
Vancouver FAQ thread has a lot of information. The first page is quite generic, and most of the more recent posts are about hotels and transportation, with a bit of commentary on local attractions.
Option 1: Best of the free stuff -- visit Stanley Park. It takes about 30 minutes to walk along the waterfront from the cruise ship terminal to the edge of the park. In the park are a variety of free activities ranging from beaches and swimming (second or third beach on the west side), totem poles (in the middle), hiking trails, and giant trees (throughout). If you're willing to spend a bit of money, there are trolley tours, horse-drawn carriage rides, the Vancouver Aquarium, a swimming pool (for people who don't want to swim in the adjacent ocean). While every family is different, mine could spend the better part of a day here.
Stanley Park also offers a unique opportunity to watch cruise ships coming under the Lions Gate Bridge, usually around 6-7 am and 4-5 pm.
Holland America Statendam and Celebrity Century will be sailing out the day before our cruise departs.
Option 2: Grouse Mountain. Once you pay the Grouse Mountain admission, there are a lot of activities at no additional cost. The cable car ride is an attraction in and of itself. At the top of the mountain, you have an incredible view of the city and harbour. Grouse Mountain hosts one of the most realistic grizzly bear (same species as Alaska brown bear) exhibits. The two orphans raised here are relatively active and don't shy away from visitors. Also at the top of the mountain is a lumberjack show, a wildlife movie, and a handful of hiking trails. For a bit of extra $, family members could enjoy zip lines or the observation deck inside their wind turbine. I nearly forgot that they have a wolf enclosure at the base of the mountain. The wolf kept here was trained for the movie and is now a retired actor.
Option 3: Capilano Suspension Bridge. It's less active than Grouse Mountain, but very peaceful if you and your family can cross the chasm on the slightly swaying bridge. There are elevated platforms and walkways (like an Ewok village), but they don't go so far -- people who don't want to climb the stairs can easily keep up on the forest floor below. The view of the gorge is unique, but you will not be able to see other sights like you can on Grouse Mountain.
Option 4: Shopping. Metro Vancouver has a population of 2.5 million, so there's very little you can't find here. Tourist shops surround the port and the historic bits of Gastown (just east of the port). Historic Chinatown is adjacent to Gastown, but it is a bit inner-city-rough-around-the-edges. Pacific Place downtown has chic fashion. Granville Island is a glorified farmers market and artist district. Oakridge and Metrotown are the most comprehensive malls in the area. Vancouver is Canada's gateway to Asia, and the city contains a very high density of modern and clean shopping opportunities for all Asian cultures. The Aberdeen Mall, just south of the airport, is an excellent location to find Chinese and Japanese stores. There are also neighbourhoods full of Korean, Indian, and Vietnamese, just to name a few.
Option 5: Museums and Galleries. All cities have museums, but Vancouver has a couple that make it truly unique. The UBC Museum of Anthropology focuses on west coast native cultures, not just their art and totem poles. If you want to learn about the culture of the people that would think nothing of paddling a canoe full of oranges from California to Alaska, this is the place to go. The Vancouver Art Gallery is in the heart of downtown Vancouver. In addition to traditional art, it usually contains some new unique exhibitions. (On my last visit, I saw an exhibition of video game artwork.) If you have a vehicle and a desire to see some history, there are a couple other museums I consider unique. Steveston is about 30 minutes south of the port, at the mouth of the Fraser River. It is a historic fishing village with a cannery museum surrounded by restaurants and shopping as well as miles of river-front / seaside boardwalk. About 45 minutes east of the port is Fort Langley, a fur trading fort on the Fraser River. Fort Langley is also a good place to watch trains carrying every kind of good to and from the port of Vancouver. I've also heard good things about the mining museum in Squamish (45 minutes north of the port), but I've never visited it myself.