I recently was on the hunt for a solid city bike that I could mount panniers on.
A reddit comment suggested the Polygon Path 3 - the best deal I could find was BikesOnline that is now 10% off at $719. Shipping is about another $30.
I was impressed by the service: I was able to schedule a phone call with someone to discuss my needs and the bike, it arrived two days after I ordered it, and when it came it was pretty much ready to go - some home assembly, but all tools are included as well as a handy instruction manual. It was very safely packaged inside the box.
As for the bike itself: it gets really good reviews, not just on the BikesOnline website. According to 99spokes it has really good specs for its price-point. Apparently Polygon is a newish budget brand (Indonesian?).
I've now been riding it about a week. I've been quite happy with it, it feels solid, brakes and gears work well. Overall I'd say it's a good deal for $719.
Polygon supplied the bikes for ALDI. Sadly have not seen them in a while.
Good specs here.