Man, if I had a dime for every time I said that. *rimshot*

Freelancer, if you can find it. Otherwise - the X games, which you can buy DRM-free on GG .

I'd start with... that's a difficult question.

At first I thought of Oolite, it's free so you can try it and see if you will like it / the genre. But as it is basically remake of 8-bit game of Elite it can has some shortcomings, like long trips from jumpoint to planet (which will get diminished later in game with witchspace injectors) and maybe frustrating deaths.

Then there is Freelancer, but I don't know if this is still selling somewhere.

X series are great, but can be a bit difficult and overwhelming for a newcomer.

EDIT: of course, Wing commander Privateer (but only the first installment) seems like an ideal choice if you like retro! I completely forgot about this until I read Strijkbout reccomendation.

As I do in just about every thread talking about space sims, I'll give my nod to Independence War 2. Here's why:

You're looking to get into the genre so it might be best to start with "lite" versions of many of the things you're looking for. I-War 2 offers trading lite, exploration medium, a linear story but with a ton of freedom to delay advancing the story, ship upgrades, and all the combat you might want. Once you've reached the point in the story where you can leave your starting quadrant / sector / whatever, you can then explore almost the entire game world at will. For better or worse, there aren't many mods for the game. On the plus side, this means you're not spending a lot time trying to get 78 different mods to all play nice together.

http://www.gog.com/game/independence_war_2 For 6 bucks it's hard to go wrong, and is a good place to get started in the space-sim genre without getting over your head with the whole open-world thing.

Sounds like X3: terran Conflict is for you. Just be prepared to spend a lot of time with it. It is a slow game, and the focus is more on creating a trade empire than on fighting (though there is, or can be, a lot of fighting in that game).

If you have a joystick, and you have no compunction against learning how to set up dosbox. I recommend Elite Plus. It can be found on most abandon-ware sites.

If you would rather not go through that process, or do not possess a joystick, I recommend Transcendence. It's a 2D space sim in the vein of Escape Velocity and NAEV. A bit more directed certainly. But it is a excellent title, and 100% free.

If you do want something in the three dimensions: Freelancer. It might be difficult to find, and your going to have to pay for it. But its an excellent start.

ARE YOU INSANE!? ID War 2 is great but the learning curve is a bitch. This is the last titles I would recommend for someone just getting into the genre. The myriad of keyboard commands is enough to make your head spin not to mention everything that goes into simple piracy like scanning the freighter, checking for escort, fighting the escort, scanning the freighter again, superficially damaging the freighter, discerning what cargo went where, discerning what cargo you should bother taking, taking it, getting to a fence in one piece, etc etc ec.

I may very well be insane in some regards, but not about this.

I-War2 isn't that difficult to get in to, certainly much less so than X3 which has been mentioned several times as a good place to start; as an I-War veteran, X3 left me scratching my head many times over. The simple Jafs mod takes care of much of the cargo drudgery from pirating. Checking for escort is easy: see what ships are tagging along with the freighter. Granted, tagging cargo is somewhat of a drag but it's also "realistic".

Not sure what you mean about getting the cargo "to a fence" - once Jafs loads the cargo and leaves the area, it's placed into the inventory at your base. Except for a few storyline in-mission cargo swaps, all trades happen from the safety of your base.

I actually started playing Privateer a few days ago, mainly because I've never played the expansion pack before, and I want to play it fully through before going to Privateer 2.

I still find it pretty entertaining for a second playthrough... but for some reason I don't feel like playing a space sim/shooter. Maybe it is the graphics, I've been spoiled by smoothly moving polygon graphics that these pixellated and jerkily rotating ships feel more like I am playing some 2D arcade game...

In fact, I think I'd probably find e.g. Elite Plus and Starglider 2 more believable space combat games (as in, feeling like being in space) just because they have polygon graphics, even if they are low res and rudimentary graphics.

The graphics in polygon space games like Freespace and Wing Commander Prophecy are quite enough to make me immersed, feeling like I am alone in vast space. Or even Sinistar Unleashed, even if it is more like an arcade game:

http://www.youtube.com/watch?v=WNY2HQ47mRM

I don't really need better graphics than that in my space games.

Freelancer definitely. I still remember struggling to find my way through a dense nebula and happening upon a secluded space station with exotic weapons and a kickass ship worth a captain's ransom. Apart from the story there is a great deal of freedom. You might notice one planet prepared to pay x amount for cargo A and another planet far away selling cargo A for less than x. Then you could start saving to buy a big cargo ship to transport a muttonton worth of cargo A between the two planets to make a killing. Of course you would have to seriously arm your cargo ship because you'll no doubt run into space pirates. Or perhaps you find asteroid belts with valuable minerals that you decide to mine to make dough. Most systems from what I recall have some sort of station as well where you can accept missions.
I've heard very good things about X2 (X3 as well unless that is the latest one) but I don't think that is the place to start.
On the top down level there is Starscape and SPAZ both of which are good. If you're very brave, and don't mind losing about 2 complete days after discovery, you could also try FTL.

The best space sim that I know of is Wing Commander IV The Price of Freedom. It doesn't have any trade/explore elements though but more than makes up for it with its production values evident from the story,music,fmv sequences and 'between-missions' activity on your ship. It had an insane production budget for its time.

Oh yeah, I forgot about that. OOOPS
ID2 is probably my fave space sim ever, I just thought it was hard as hell to get the hang of. Of course, when one thinks of things "quick learner" and "smart" I'm usually not the 1st name that comes to mind. :D

I-War 2: Edge of Chaos has both linear and non-linear play. Looks pretty damn good even today. I-War 1 is way more hardcore. Both are among my favorite games :)

In fairness, I'd played a bunch of other, lighter sims from other genres before getting into I-War2 when it first came out. If a gamer has the hang of, for instance, a mid-90s helicopter sim or one of the lighter aviation games from the 90s, then the bar isn't necessarily a major hurdle to clear. The most modern aviation sim I had played before I-War2 was, I think, Eurofighter 2000. That one was complicated enough (though not Falcon 4.0-complicated, from what I've read) that it was a fairly easy transition.

So the caveat to appease us both: if one has played other vehicle sims, I-War2 is a decent place to start for space sims. : ) On the other hand if one has that experience then maybe the X games aren't a big leap, either.

I second that motion.

Thanks for all the suggestions!

I'm going to try and hunt down a copy of Freelancer. If I have no luck there, I've got Independence War 2, Darkstar One and Wing Commander Privateer on my GOG wishlist. I've heard a lot of good stuff about X3, but I think I'll take the advice of several of the posters here and save it for later once I've had more experience with the genre.

For now, I've got the shareware Elite 2 downloaded, as well as Oolite, which I'll give a try later today.