Beartooth Pass and Million Dollar Highway are both fantastic rides, no doubt about it.
However, if you're ever in British Columbia do yourselves a favour and ride Trans Canada Hwy #1 from Spences Bridge south to Hope through Fraser River Valley and you'll be riding my all-time favourite ride. I've ridden it south to north, but for the best views the best is from north to south.
Mountains on both sides of a raging river, CP Rail up one mountain base and CN Rail up the other, both going through multiple tunnels along the way. It truly is a beautiful place, that wouldn't be complete without a visit to Hell's Gate.
It would actually be really cool to do all three roads on one tour just to see them one after the other, but my money is on #1 in BC after doing all three albeit at different times.
With everything else that BC and Alberta has to offer, it will definitely be worth the trip, and I hope you get there someday. You won't be disappointed.
Ride safe,
Mike
PS - I almost forgot - Congrats on hitting 200,000, very impressive!