Rimowa Salsa Air. Going strong here after about 7 years of frequent flying. The shiny outside quickly shows scratches but wheels, locks, zips and linings are like new.
If you know you won’t be in economy much / at all and weight isn’t an issue, then get the alu versions.
If you know you’ll be nervously checking in luggage and hoping for minimal excess charges (2 adults, one infant checking in 175kg is a family record) then the light baggage is great.
edit: completely missed the point of your post 🙂 Why not 4 wheels? Makes life much easier? They can always be used using only 2 wheels, should you wish to make life harder!