Logan Pass area
This is a very popular area with tourist since it includes the visitor center at Logan Pass, whose parking lot gets full by 8 am in many days. I have hiked the Highline trail, Siyeh Pass (in a loop), Piegan Pass, and the small hikes into St Mary and Virginia falls, plus Hidden Lake !!
I have hiked Highline trail two times, one of those I hiked it like a loop by arriving to Granite Chalet and then taking the trail to The Loop bus stop (which then you take a bus to take you back to Logan Pass visitor center). That four mile trail from Granite Chalet to the road is incredibly boring, a forest fire burned the trees and I hated it. The other time I arrived to Granite Chalet and just turned around and hike back to Logan Pass. The hike is leveled enough that this is not a big deal to do.
When you are within visual distance of the Granite Chalet, there is a side trail to your right that goes all the way up to the top of the Garden Wall, with a spectacular view of the Grinnel Glacier on the other side of the wall. The view is amazing and incredibly windy. I won't lie, whoever created that trail decided that fuck-the-switchbacks and it seems like a 30 degree incline for the 3/4 of a mile hike up to the top. I have seen young people quit midway, PLEASE DO NOT !!! The view is worth it.
Ok, the hike that all tourist do and I recommend also (with a caveat) is the Hidden Lake hike that starts behind the Logan Pass visitor center. The trail is mostly build on wood since the area tends to be pretty wet and that saves people from eroding the grounds. There is a side hike to the top of Reynolds Mountain, which I hear it is very easy to do. Below you can see the view from the overlook.
and here is my caveat ............... hike to the lake !!! That is, if the trail is not closed due to bears, meaning from the moment you leave the overlook this is no longer a tourist hike, but a hike that you HAVE to have bear spray. The views of the lake are tranquil and no one goes there. Again, PLEASE keep an eye for bears when exploring around the lake.
Ok, the other 'loop' hike in GlacierNP is the Siyeh Pass hike. There are two things you can do here: (1) make it a long day hike by hiking to Piegan Pass, turn back and the go to Siyeh Pass, go down and then take the bus to return you to the start, or (2) just do the Siyeh Pass loop and that is a pleasant day hike.
So you start at Siyeh Bend (there is parking along the road). You hike 100 yards along a creek and then make a right turn and go up a heavily forested area (make noise for bears). The incline is pleasant, so it is not hard to hike. You will then cross a couple of nice creeks that will open up the view.
Ok, on to Siyeh .... before you start the hike up to Siyeh Pass, you are located in an area called Preston Park .......... turn around and you will get this spectacular view:
Keep going down, peeking at your right to the creek that will eventually feed Sunrift Gorge (once the glacier is gone, so will the gorge be gone). Now, if you want to do more, cross the road and visit the St Mary and Virginia falls, very popular with the tourists.
Something that I plan to do next time is to climb Mt Siyeh. Google it and you will see the amazing views from the top.