Empty.
Yep, we use that word a lot. We use it to describe the current state of various things. The fuel tank in your car, the last beer bottle you had, Paris Hilton, etc, etc...
But how empty are things? For example, an empty pool still has air in it. So does your fuel tank.
Okay, so let's pump the air out and make a perfect vacuum. Fuck yeah, that's pretty empty, right?
Well, we still got photons running around, not to mention electromagnetic waves and all sort of radiation and shit.
Right. So we go to intergalactic space. Away from everything and make a completely sealed box. It's shielded from radiation, photons and all kinds of shit. We pump any type of molecules out and now we have a perfectly empty box.
End of story.


**Roll end credits and plays some light music**



Hold on now, motherfuckers! That shit ain't that easy! At the end of the day, that intergalactic shielded box with the perfect vacuum still has one thing in it. Space.

That's right. Space. And what a little bitch it is. This is what is stopping us from booking a holiday in the Horse Head nebula
Now, unless your education comes from the back of cereal boxes, you should know that there's an arbitrary speed limit to all things.  The speed of light, or about 1079252848.8 km/hr ( That's 670616629 mph for those of you who still live in the 19th century). Now that's pretty fucking fast. You could travel around the earth nearly 8 times over in one second.

But let's look at this in into the concept of space. Let's say we have a fully kitted out intergalactic space donkey that can travel at light speed. Our donkey can takes us to our moon in about 1.3 seconds. Not bad.  
Now let's take a trip to the sun. Our plucky donkey will take a bit over 8 minutes to take us there. Not bad you'll say. But let's see what happens if we try to go to our nearest neighbouring star system, Proxima Centauris. I hope you're into donkeys because you'll be travelling about 4.2 years to get there.
Yeah, you and that donkey will be pretty fucking close by the end of that.
And now, just for shits and giggles, let's say you wanted to go to the other end of our galaxy. That donkey will take one hundred thousand years to get there. And that's by flying straight line with no stop overs for food, peeing, sleep or whatever else you do with donkeys.

Now I'm back with my point about emptiness. The speed of light is limited by how fast it can travel through space. It is the interaction between objects and the fabric of space itself which sets that speed limit.
For an object with mass to achieve light speed it would need all the mass in the universe to be converted into energy so it can propel itself across at light speed (am I wrong with this? If so, please let me know). Getting to 99.99999% light speed is not an issue, they do it all the time at particle accelerators, but anything with mass cannot reach light speed itself.

In sci-fi, they love the faster than light travel concept.
Theoretically, it is possible. However, whether they are practical or not remains to be seen.
One of the favourite forms of travel in sci-fi is the wormhole. This is a tunnel, a shortcut of sorts, which connect one part of the universe with another. Problem is that for this to be a shortcut, the universe itself would need to be folded, otherwise the so called 'shortcut' may take even longer to get there than flying through normal space in a straight line.
Another method would be the one theorised by Miguel Alcubierre Moya, Mexican theoretical physiscist. He has mathematically devised a system where your space donkey would be in a bubble, space would be compressing at the front of the bubble and expanding at the back of the bubble. However, inside the bubble, space would remain perfectly still. This would propel you at light speed, however, should your donkey move from the back of the bubble to the front of the bubble, your donkey would technically be travelling faster than ligth. Problem is,  you wouldn't get to where you were going any faster than before. That fucking donkey.

So how do you travel to other galaxies without your tea getting cold? Well, you could break through the brane that holds our universe ('brane' is short for membrane). Let us assume that your donkey does a mighty mule kick and breaks through the fabric of space and steps outside our universe. If we find ourselves in absolute nothing, the speed of light does not apply. If there is no space, there is speed limit to hold us back.  You could travel much, much faster than light to a desired point, then punch a hole back into our universe and step somewhere in Andromeda and still have a nice, hot cup of tea while watching three-breasted aliens do nasty things with your donkey.
Problem is though, once you step outside our universe, what is absolute nothing like? Would matter completely fall apart? Perhaps we need some sort of space bubble to support us. And if this 'space' is multidimensional, not just the pissy three dimension that our brains can deal with, how would we navigate through it? And if there is nothing, perhaps dimensions are nonexistent there. How can we move through nothing?

Oh well, perhaps I'll let the donkey worry about it.

Edit- I forgot Quantum entanglement which is instantaneous no matter the distance. If you entangle every particle in your body to another object at the other side of the universe, you wouldn't even need to travel there.

Edit 2- I looked more into Alcubierre's warp drive. Apparently, it is able to propel you to speed faster than light.  during the big bang, space was supposed to have inflated at speeds much, much faster than light. So maybe it would still work.