Difficult question. In fact, I consider the first Privateer one of the best games of all time.
The problem is, I can't really describe why. I've always wondered what makes it special, and could only boilt it down to "atmosphere". The thing is, I can't say what makes it so incredible atmospheric. I can only find cues, hints - things that lack in other games. Or that are too much in other games.
X³ comes pretty close to that Privateer feeling - I really love that game, but it has a few flaws. Luckily, those really are minor flaws, the game is highly enjoyable.
Things I like:
-Landing on planets. I really miss it in X³. Remember New Detroit? It sends shivers down my spine. The never ending rain, the hover cars like in Blade Runner, the landing pad on a highrise... what an idea! What a setting! You could use it as a filming location!
Planets can be made so much more unique than space stations. And I loved the feeling of "coming home".
-Moving around space stations / planets. I don't mean ego-shooter style, it could be just a few screens like in Privateer. That makes New Constantinople so different from Perry. Those stations had flair, they were unique. Truly unique.
-Which leads to the next point: Different things should take place in different locations, not just by pulling up a new menu on the main screen. Ship Dealer? Walk there. Look around. Even though you can't move, no matter. Just don't put me on the landing pad and let me pull up a menu.
-Graphics. I love graphics. That's why I play a game and don't read a RTF file. I can mount a new gun? Let me see the illustration! Let me see my ship! Show me the gun mounted on my ship! I loved that part in the equipment screen in Privateer. Each item was illustrated. And heck, I could see where it's mounted on my ship! In X³ I can only try to find out where a gun is mounted, I can mount it in space (which makes it quite easy), and I don't know how the gun looks like.
-What I love about X³ is the possibility of owning several ships. It's totally worth it.
-Also great in X³: the vast universe.
-The overall designs of the old Privateer rocked. The looked simply real. Let me put it this way:
3d graphics tend to look too "clean". Now the old Privateer had only "painted" images, yet they looked more realistic, than some 3d scenes. Uh, I think this post gets pretty confusing, especially for a first post. I better stop here, sort my mind and post something better later.