Well, Samsonite is one of the more popular ones, Away or July if you are a hipster, Rimowa if you have money.
I don't pay attention to brands but rather I pay attention to design, material, pockets, locks and more importantly, WEIGHT.
Lots of smaller airlines have a 10kg or even 7kg carry on. They are all various sizes, not standardised. You need to look that up then get one that fits the smallest one just in case.
I had one that has an external compartment for laptops which was handy when I want to take it out at the airport to use or on the flight from overhead instead of having to open up the case.
I like hardshell now, but the problem with most hardshell is they do the 50/50 opening, splitting it in half, making packing single large object souveniers difficult if you need to. Generally not a problem.
TSA locks would be handy but not end of the world as I can use my own.
But it has to be under 3kg, 2kg is what I aim for in a carry on. The new PeakDesign one is 4kg...which is insane.
And get a random colour, just in case it need to be checked in so you can spot it easily when it comes back on the carousel.
£50 TK Maxx special, where I have always gone. But I did blow £75 on a Versace one in TK Maxx once! (breaks some of the rules above, black, no lock, soft shell lol)
For check in, hard shell definitely. I got mine in Singapore...cheap like £50 too from a department store.