Easily the best hike in all of Colorado - The lakes, the mountain views, the wildflowers. It's just tough enough to be challenging and is beautiful throughout the entire hike. I suggest camping near the trailhead, makes for an easy start and no parking issues (but seriously, if you get to a popular trailhead after 9am and are pissed it's full... you're an idiot). We started around 5am; about an hour in we heard a huge group of coyotes howling off in the distance, presumably about a recent kill, and it was very cool. We didn't see anyone until we were past halfway and started seeing backpackers coming down. When we got to Ice Lake, we were the only ones (on a holiday weekday!) and it was extremely special. Island Lake is definitely worth the additional short trek, but it's not as electric and jaw-dropping as Ice Lake.