Games similar to Freelancer?

Check out the X series, it's more of a sandbox than an rpg, but it's one fantastic attempt.  Not quite what I'm after myself, but the AI has yet to be written to build an empire from your privateer in the midst of an interstellar war between actual powers instead of just scripted events.

If X seems to be your cup of tea, beware.  The system makes freelancer look like a joke, which it is in retrospect.  I had fun with it, but the game is nothing compared to X3.  Oh, building your massive empire will make games like crysis feel poor in the system requirements.  The recommended specs are insufficient to the task when it comes to sending a fleet into battle with other fleets, which is something you can actually do in X3.

Hold your horses here, are you saying this is a third person game, where YOU can build an empire? In a third person game?! That sounds amazing.. I got to check this X3 game out.

Wait how does it work though? Do you have a fleet following you around? Oh and, I've got another question, is it possible to dock planets in this game? Like in Freelancer?

X3 is EVE without other people, so take that as you will.

X3 is pretty cool.

However, you need time. You start as a little tiny independent trader and go from there. It takes time to actually have the money to sustain a fleet (You can even buy a whole star system at one time...). Yes, you can have a huge fleet and start conquering if you feel like it. But, honestly: It takes time! (In the new "X3: terran conflict", which is independent of the other "X3: Reunion" (more like an X4), you seem to be able to even hire marines and boarding parties, which then capture enemy vessels for you...) However, the main focus is on the galaxy wide economics which is in real time...

For X3:Reunion there is a pretty good fan mod (actually a finished playable mod!), which adds new sectors to explore and new missions, as well. They included sth like a fast start, in which you can choose to be a trader who already has a decent amount of money. That really speeds up the gameplay. (However, I wanted to make it on my own and started the game vanilla style... It took ages... And at one time I simply focused on other games...)

In general, X3: Reunion is IMHO warmly recommended.

X3 Terran Conflict, an expansion to X3 Reunion will allow you to make money faster because the pay outs from various different type of missions are larger.  Much larger.  But if you want an X game that has more depth, as in more immersion into the X universe, then X3 Reunion is a much better choice, simply for two reasons, the BBS system is in X3 reunion, and it is not in the latter one.  The second reason is that there are more mods and scripts for it made by the community.  See many people in the X-community plays their game with mods installed, it makes the game extra fun.  

Since no one has explained it yet, details.

Taking X3:Reunion's main plot as the starter.  You start out a lot like Freelancer, a pilot with a ship.  There's new badguys popping up and nuking people out of nowhere, a generic badguy.  You go through the missions, trading and blowing up pirates to advance yourself, a lot like Freelancer still.  Eventually you win and are left with no more serious badguys to exterminate, still a lot like Freelancer.

What's not like Freelancer at all is the system in which the campaign takes place.  You have a property management system that lets you deploy ai pilots in multiple vessels.  You can buy freighters and run them manually in that management system through orders, or you can pop a higher level trade computer in them and automate the bastards entirely with the click of a button.  You can form flight wings, set groups on system patrols, set up mining bases on asteroids, buy factories, battleships, carriers, even obtain a space station for producing ships yourself, all without the use of mods.  They have a simulated economy too, weapons are built at weapon factories, using components that come from other factories, built by raw materials mines from asteriods, with energy from solar panel stations being the juice that makes them all run.

Unlike Freelancer, you can build up an armada with your own industrial power behind it and wipe out entire systems in glorious fleet on fleet battles with carriers, battleships, and hundreds of fighters.  It's beautiful, although this happens at a couple fps if you're running anywhere near the recommended sys reqs...

With mods, specifically Xtended, the game is pure badass outside of that minor issue I previously mentioned.  There's something very empty in beating script driven opponents, if the races were actual sides with their own motivations, I'd be in heaven.  With the right mods though, you can systematically exterminate them one system at a time and clear the entire galaxy of all that reside.

Edit: Ship capture!  Can't believe I left that out, pilots have a chance to bail out when you kick the crap out of them, leaving you a damaged ship that you can take posession of.  Freighter captains even dump their cargo for you frequently when you attack them.  Piracy really does pay in X3. 

You might be interested in the upcoming game Jumpgate Evolution (or the still active but dated Jumpgate).  Combat space flight simulation with role playing aspects.