I believe that the ET's would choose to travel in a more comfortable environment than a flying saucer. Flying saucers, Rockets and Metal spaceships is SO very human-like thinking. Just MHO... I think that "aliens" would choose to travel the dimensions and multiverses in thought-controlled biospheres that fits their needs and way of existence. But what do i know, other than, that i know nothing?!

And of course, i do know that it's the catchphrase from "The X-files" & BTW Gillian Anderson is getting hotter & hotter every year ;D

Something like this. They'll use a kind of biosphere-capsule or cryosphere-capsules. But one day we will know what the best way will be...

The best way for earthlings to travel in space is to not travel into space but to stay on Earth. Earth-born human beings are not fit for long term travelling in space. No earth-born human will survive more than max. 7 yrs in space/on other planets. The best solution for humans is to send androids/robots and remote control it all here from Earth.

Till the human mankind we be able to do long trips with a target, they'll find a way to stay fit and alive. but this might cost a few decades.
I'll still dream of something like star trek

No worries; Keep on believing & dreaming, MrScotch.