I am from Vancouver op, though I live in Portugal now.
Both road trips would be amazing.
If you did the Vancouver to Banff road trip, via the Okanagan and Northern BC, you'd see some really cool areas: Harrison Hot Springs, wolf lake, Hope, some wineries, Penticton, Kelowna, Oliver, smaller blue collar villages that make you feel like you're living in a bygone era, some of the most beautiful lakes and mountains into the world, etc. Wildlife will be hit and miss, and Banff/Lake Louise/Tourist activities are crazy expensive. Also tons of time in the car!
My preference would be to do Vancouver for a few days, then fly over to Victoria on a sea plane (an experience of itself), then do a round Island trip. Must sees are: Kingfisher Spa, Tigh Na Mara resort, Parksville, Victoria, Sooke Pot Holes, Tofino, the Place with the Goats on the Roof, Qualicum Beach, and maybe a few other islands if you have time: Salt Spring and Pender are my favourites. You can do whale watching, kayaking, canoeing, lots of walking and hikes, stand up paddle boarding, and a good mix of modern and old - era towns. Still loads of beautiful lakes, wineries, food places, potential places to see wildlife. Less time in the car / more places to stop. You could do a day on Grouse Mountain in Vancouver to see some animals, albeit not in the wild. Vancouver you must also do Fly Over Canada, Granville Island, water taxis, Stanley Park (cycle or roller blade around the sea wall), Gastown, Chinatown... lots to do.