Video games are an ever evolving medium. It may not seem that way right now, what with annual releases of the same ole same ole; I'm looking at you FIFA, Mario and COD. In years past, the rate of new ideas and new concepts coming into games was much higher, which makes sense since developers only really had their imaginations for inspiration. There wasn't this huge body of existing work for them to look at and be influenced by. So there was constantly new ideas and concepts being experimented with which sometimes could lead to new genres of games.
I'd say the first Killzone was also ahead of its time. The dev team pushed the PS2 beyond its limits, and the game suffered from frame rate and glitch issues as a result, however we have seen what the developer is capable of with Killzone 2 and 3, which arguably are what the first game should have been had the hardware been there.
There's always hardware limitations that prevent a game from being fully seen to its potential. All the games on the list could have been more popular with better hardware and a good marketing push a la Gears of War for example.
Starflight was epic in the scale in which it worked with thousands of systems being rendered in realtime. Even the developers hadn't visited them all. It had a funny state savegame method, which meant you had to save before you exited the game, otherwise it would not load the next time. Still an awesome game with a great story!
Both are available on GoG.com for a paltry sum. I heartily recommend both!