Leuthold Couloir is the next step up from the pearly gates climbing route on Mount Hood.
The Pearly Gates Route on Mt Hood is considered the standard approach. It still requires some skill on ice.
Climbing Mt Jefferson via the southwest ridge is the easiest route to accomplish in one day. It will require route-finding and alpine skills.
The Climb of South Sister in Oregon felt very similar to Mount St Helens. It is a well-cut low-grade climb on a lot of scree and snow.
The climb of Broken Top has been on my list since standing on top of South Sister Last Summer. Most of it is easy, until the last 200 feet.