Counting on Rainier views in Seattle is a complete toss of the dice, given the cloudiness. I fly AA through SEA every 3-4 weeks, and honestly the best views are typically on departure, not arrival. Most recently I got some great shots from the left side of the aircraft. Arrival shots are mainly night shots (sometimes less cloud), also left side.

I could fill posts with multiple Rainier shots, but none as good as standing on the summit photos (been there 2x).