I always thought a series of missions which would form it own mini plots with a bigger story going on in the back ground would be a good way to go like the TV series Babylon 5, DS9 or Battlestar Galactica. Each planet would contain a number of mini plots along with the more generic missions ie the bring, get or shoot ones also expanding the core jobs as the recent GTA 5 has done with the bounty hunting job ect.

Seamless planet to space transition in itself is pretty cool.  If you can pull that off with some procedural coastlines, mountains that roughly conform to known geologic principles, etc., then I'd say you are well ahead of the curve.

Also throw in some Gas Giants and Super-Earth ocean worlds, as current observations seem to indicate they are fairly common.

Also, (wow, this just keeps coming) how about some Venus-type planets with super-dense atmospheres.  Atmospheric flight physics ala X-Plane is also an aesthetic direction I'd favor over magical "anti-gravity" as much as possible.

 

On a side note one of my ideas was to drop seamless planets and space and provide  "sites of interest" on worlds that would pop up and could be traveled to

 

Limit Theory rely on this mechanism (It seems to me).

 

what do you guys want to see/do on these planets after you land on them or while you fly across them?

 

Collecting and studying ruins and artifacts of extinct aliens civilizations, trying to decipher the clues to undestand why they disappeared (as in the J.McDevitt books)

Jack McDevitt writes very good tales - Ancient Shores is one of my favourites!

Obviously planet to space. But that's already been done befor e in Evochron Mercenary. What I'd like to see is a somewhat detailed procedurally generated planet with outposts, dungeons, explorable areas, etc. From all the procedurally generated stuff I've seen, I think Minecraft does it best (especially with mods). I'd like to see a mix of hand crafted and procedurally generated. But I think a vast and interesting PG system is years off from being perfected. For example, imagine combining skyrim and Minecraft. I'd also like to see life added to the planets. Different towns, factions, different animals or breeds on different continents. Deep sea exploration.

In exploration games I would like to have something that gives me some sort of direction or incentive to move around. Farscape plot is perfect for such a game. You are basically escaping a deranged military commander trough unmapped space that hides all sort of interesting locations. You are not really railroaded towards any destination. You are just discouraged from staying put for too long. Thus you must move and as a result explore all kinds of places.

It would be interesting to gather landscapes, skies, sunsets images, weather information etc. as much as possible to make simulations and go beyond our vision.

Making VR simulations, so we stop searching for roads on Mars. Put human brain out of million years experience and have new ones. To look differently to what we got used to.

For example, Azimov works are gnostic, bring them closer to our new nerve experience.