personally i think that my own fave ideas are the obvious, more of everything, ships, planet types etc etc
but my main ones are these:
Campaign+new race (the new race could be the ones chasing Vasari which leads in with possible campaign ideas but who it is, is not important and tbh a new race is not essential to me)
only slightly better graphics on maybe a few ships and things, i think all weapons should look good, especially the big ones when fireing, for example ime not sure if anyone else gets this but my Advent Radiance is my fave ship, when it starts to charge its super beam and i wait suddenly it fires in a beautiful blue beam, could be a little better but its nice, but then i zoom in and find out many ships may be taking damage yet theres no effects on them, its like their just taking damage strangely, which is cool, i want to blow many ships up but with graphical effects on it, like an aura coming from the beam or many mini bolts of energy sparking hitting all ships affected, then when i look at the radiance the beam is sort of floating off the bottom of the ship too much, not coming from an overall weapon
maybe an extra 2/3 new cap ships per side
Another important thing is that i woud like super capitals like many many people have said, although it may not be possible, beautiful ships like from star wars equel to Super star destroyers, in EvE the massive battlecruiser sort of things, its those ships that are great, the capital ships are awsome but we need a really big monster that you hyperspace into a grav field or it comes into your and you sit for a second drooling at the majesty then realise its enemy as your eye twitches with fear and you say "holy f***" lol, it would be an awsome ship class, i think they should be super but only one per player and perhaps 2/3 choices of super cap per side to follow strategies such as a super carrier for fighter players or a massive bruiser of a battlecruiser for ship to ship battles.
ideas could be:
massive Advent ship with onboard beam much like cleansing brilliant only far larger that rotates from an enormous front mounted axial canon, equiped with incredible damage, and soak, highest mitigen ship, highest shielding of any ship and with weapons to completly eliminate large groups of ships (by large maybe 6 capitals, handfuls of most of hte other ships) basically a fleet unto itself
you could also have Advent Psi ship, with like some awsome sci abilities, planet capturing in one shot, freezing all ship weapons and drives for like a minute, mind control capital ships etc etc
for the TEC have heavy armor, long range, more weapons than most other races, perhaps not equel to the power of the advent super ship above but with longer range, faster cooldowns, speed as well as more weapon coverage overall, (aft weapons, starboard etc etc)
Long range planet "destroyers" capable of completly elimnating a TEC thread from long range if its planet, maybe even have a massive AOE nuke missle barrage
another important aspect of an exp would be perhaps new super weapons, like the weapons above and like many people ahve said i think there should be planet destruction available if its too far gone, or if your really not interested in having the planet.
Ofc to balance (and for more fun imo since it gives primary objectvies in minds of players) there could be notificantions of finished uber weapons and super capitals, perhaps massive additions in metal and crystal+credits for defeating them as well as long build times for them, making them look amazing in contruction as the shipyard is prob huge or the hundreds of tiny nano bots swarming the huge form of the slowly building leviathan