Star Citizen for me seems like the most ambitious.

Star Citizen is still way from it's release, it's unknown if they will finish it in time. So I'd wait with this one.

E.V.E. is very expensive if you really intend to sinkinto it. And you will still be a massive disadvantage compared to ppl who started years ago.

SO I vote for Elite - it looks amazing, gets awesome feedback from anyone I know who already played it and I am waiting for it to become cheaper to get it myself ;)

In case you havent heard about it, FTL Is a very good rough like indie game where you control a crew in space to manage a spaceship and survive in a suicidal mission. The game is great fun if you like this sort of game, also the game haves great replay value as it is very tough, and even if you beat it there are still new ships and challenges to unlock + there are tons of mods including ships from Star Wars and whatnot.

That is my personal recommendation as I have never even heard of this games on the "vote list".

i'm still waiting for something like freelancer...

Space engineers is a good sandbox game.
Dead Space 1 & 2 is you like horror/action games.
Any -good- Star Wars game.

I just wish they would remake Colony Wars from the PSX. Loved playing thoses games.

Keep an eye open for No Man's Sky.

dead space 2

or endless space emporer edition

Kerbal Space Program - it's a great game and way cheaper than the games on your list.

I don't think Borderlands the pre sequel is space per se, but it has some cool things going on. Or so I heard.

If you haven't tried it already, take a look at X3: Albion Prelude. It's like the Skyrim of space sims. Lots of places to explore, lots of stuff to do. Lots of freedom. There are other titles in the X3 series, however I believe Albion Prelude was the last one. The very latest title in the X universe series is X: Rebirth, but as I've heard, it's a steaming pile and should be avoided.

Starbound is a space themed Terraria with even more content if Terraria is your kinda thing

Star Wars KOTOR