Well... Have you given Warsow a try? It's free here on GOG, so if you don't like it you'll at least not have wasted any money :)

warsow resembles a very old game called nerf blaster, it was an epic game but no im looking for more brutal terrain and texture, and i know quake 4 but never played it but im gona try it very soon

Hard Reset.

Your post gave me cancer, OP.

If you're interested in a science fiction and maybe willing to branch out a bit, space sims might be something you could enjoy. Descent + Freespace on GOG are great options with modernizing open source engines (open source engines can be downloaded elsewhere) - the Freespace one is particularly nice (the Descent one might be too, but I don't know that as well). Both are playable with mouse + keyboard and they might scratch that itch for sci-fi combat. Descent in particular is often glowingly reviewed as an FPS action-space sim hybrid (I've not played it myself).

blake stone

Nobody's said Borderlands 1 & 2? What's wrong with you people?
Why not just go the whole hog and suggest Hover Tank 3D?

The original Halo is awesome. Don't care what anyone says.

Crysis and Crysis 2 are not true sci-fi really but close, and veryyyyyy good.

Reaching way back the Star Trek Elite Force games, Star Wars Dark Forces games and Star Wars Rogue Squadron are all good.

Borderlands if you like loot and no story.

If you can handle third-person Dead Space 2 is one of my favorite shooters this generation.

Star Trek Elite Force 1 and 2

+1 for Republic Commando, although i can't seem to get it to work in windows 7 64 bit though :/
+1 This as well :)

I think AREA 51 is ad sponsored now too isnt it? - so almost free

No idea mate. Played the game a few years ago .Lost my copy tho :/. David Duchovny doing the voice overs was a highlight :)

and manson as the... (insert spoiler here)... im sure it is - gimme a mo...
(will edit this post)

EDIT: Checked - seems it was part of midways messup (or have i posted the wrong company there?) - either way there IS a version available from SI, GH etc - though the nature of those sites on occasion still leaves me dubious. be great if it was true. Anybody have any better info?

I realize this is slightly troll-bait topic but for anyone interested.

Section 8 Prejudice is very Halo inspired, you have big glowy shields and similar weapons. The maps are large though with objectives, and you respawn from the sky each time.

GFWL though.

So Crysis, which is set in the future and explores potential technological and political developments, along with alien encounters is not true sci-fi, but a game set a long, long time ago in a universe of sword and sorcery is? :P