When compared with the likes of Ryanair, we think easyJet is probably your best option for budget flights. However its new 'cabin bag guarantee' says that only bags measuring 50x40x20cm or less will definitely be allowed in the cabin with you on busy flights. If your case is any bigger you could be in for a irritating surprise if you're off somewhere popular.
So, those flying easyJet a lot should look at picking up the Samsonite New Spark Upright 55/20. Measuring in at a diminutive 50x36x20cm, you won't have to faff about with your bag being chucked into the hold. It uses science and stuff to maximise the volume so provided you're not trying to pack the kitchen sink with you can stuff a surprising amount in there. Plus, while it doesn't weight that much, it's tough enough to withstand being knocked about.
If you're a frequent easyJetter or simply eyeing up a new case, you're not going to go far wrong here.