My favorite weekday AM ride is a 25 mile out-and-back along Lake Michigan. The turnaround point is a peninsula that juts out into the lake and has a fantastic view of the Chicago skyline. I'm typically out there as the sun is coming up over the lake. I love this route because 95% of it is on an off-street paved trail that is very busy on weekends, but at 5-6am on a weekday is usually pretty empty. I only have to navigate a few blocks of city riding to get to it.
I've seen so many amazing lakefront sunrises while riding this route. Here's on I took recently: