My favourite travel bag is my navy blue longchamp le pliage bag. It's big enough for everything I need, zips up securely, is easy to wipe down and folds up small and flat. Every time I go away I contemplate almost all my other bags but always take the longchamp and am always glad I did while I'm away.
I don't worry about it on the conveyor belt at the airport, under the seat on the plane.
Its the Eiffel Tower edition so it feels much more like its "for travel" and I have a blue lv luggage tag on it with my children's initials on it and an Eiffel Tower key ring on the zipper pull. I'm getting exited for my next holiday just thinking about it. My tip is to customise whatever bag you get in some way as its such a fun thing to do for a travel bag. ❤