There's tons of good scifi rpgs, you'd have to be major gaming snob not to find
something to your taste (though I'm sure there are folks like this).
If you like hard scifi, your best bets are the aforementioned
Transhuman Space and the
Jovian Chronicles. The Jovian Chronicles are supposed to have the most realistic ship technology in SF gaming.
The next game out on the firmness scale would be
2300 AD (aka Traveller 2300 - which is actually entirely unrelated to Traveller). Out of print, but available in PDF. QLI/RPGRealms is publishing a
2320AD Campaign Setting adaptation of the T20 (Traveller d20) rules in the future.
Then there is
Traveller itself, in many editions and forms, with or without the official setting. As an aside, I will note that T20's damage system is NOT VP/WP, even if it superficially resembles it. Damage vs. armor is handled much differently, in a more appropriate way for Traveller weapon and armor technology. WotC releasing VP/WP to the SRD has no bearing on T20. QLI/RPGRealms is working on a new player's manual (extra player crunch without the Ref-only design stuff), but its not a new "edition", per se.
Traveller lies in the middle of the hard-SF-to-space opera scale, so moving along we find a lot of options opening up. Starting with D20 Future, Babylon 5, StarGate SG-1, etc. I'm less familiar with this stuff, but I think there are plenty more good SF games out there.
Finally, if we're willing to start stretching boundries, there more choices in the "science fantasy" realm. I personally think
Fading Suns is the coolest setting EVAR, hehe... (The Holistic website seems to be having some "issues" atm.

) Dragonstar obviously falls into this category as well.
While Shadowrun clearly fell from the cyberpunk tree, you can call this sci-fantasy as well. In fact, by discarding some of the more obvious fantasy and cyberpunk tropes, you could use either Shadowrun or Cyberpunk as SF game mechanics.
Lotsa good choices...
