Joolz Aer + is great. It fits in the cabin lockers too.
It really depends how much you want to spend. We just used a traditional pushchair. Silver cross pop I think it is that I found for £15 in a charity shop. Not worth the £170 it is new! Worked perfectly well for us. We have a Joolz pram and they are so well made so I second the fold up Joolz pushchair if you want to splash out
I would buy secondhand…and the three you can’t go wrong with are the Stokke YoYo, the Joolz Aer and the Bugaboo Butterfly. All cabin approved. I would have gone for the Joolz but we fly A LOT and the Stokke is so widely recognised by all airport staff so we have no hold-ups proving it fits! Very happy with it!
We have the silver cross Clic which has been great for holidays