Fading Suns is more doom and gloom game. It is dark and brooding.
DragonStar still has to come out with the galaxy book but has the feel of a space opera game and gives me the greatest flexability as a DM to design my campaign. I think DS ofers the best chance to build a good space opera game. I would love to see small bookets in the traveller make on sectors, planets, and such.
Star Wars - well, you get trapped in another person's ideas and vision and sometimes that is a conflick with what you as a DM have planned.
Traveller d20? Not out (yet) but the last few versions just have not been up to what this game was.