So.... I'm probably not the person to ask since I am always toting my computer when I travel and therefore need a bag that has enough padding/ protection to allow this.
My commuter backpack and travel is by Bellroy and I love it. It is strictly for the plane/ boat/ train/ bus or car trips -- I rarely use it as a regular daypack because it is larger than I'd like for that and in summer months would make my back too warm. But I have worn it as a city day pack in colder months and it's excellent for that.
I also have a convertible tote/ backpack by Bellroy that I use sometimes when travelling more casually. This does not work for the computer but it's a brilliant picnic type of bag -- has a bit of insulation and space for water bottles, etc.
I am actually looking for a nice looking daypack myself, not gearish but capable of going for a day hike and so on. So I'll be following suggestions here.