I've always used the plastic airline-approved carriers.. no problems. I prefer the ones with snaps instead of screws, as we lost a nut in an airport one time, and they're fiddly anyways. (Sometimes security wants the cat taken out of the carrier so they can X-ray it, and my cat really wouldn't go out the door.) If you're coming to the UK, you might want to be looking at dog carriers, too. My tiny 9 lb cat needed a mid-size dog carrier for the DEFRA 'standing room plus ear space' rule.
If you really do have a small tiger, ask your vet and the airline/DEFRA/ whoever about custom made crates. I saw a few wooden crates arriving at Heathrow when we got in.