STALKER is magnificent!

I played mass effect after stalker, and it paled in comparison. I'd rather be chased by freaky mutants in the dark with only a near depleted flashlight and a few shells for an oversized handgun, darting through life - theatening anomalies then be chased in a confined spaceship by ... blue ... freakish alien women (and Tali doesn't even chase after you >:( ) or christian poetry addicts who are out to steal my mental virignity. And I'd rather be torn to shreds, burned, electrified, sniped or compacted (yes, that's a thing in STALKER) and having to try again, then breezing through bland enemies in concrete corriders with the slightest of plots to fuel you onwards, checkpouint saves et all.

The gunplay is fine, high level difficulty is just the right kind of dificult, there are masses of mods (try lost alpha ... or misery, for those masochists), there is variety of good enemies, from brain-scorched gun toting cultist to shady mercenaries and mutants (a whole assortiment). There is a big world to head out into, and the story is just good for the game it is. There are nice guns, and enough little missions to keep you busy if you want to make some cash to be able to take on tougher missions.

And the ending more often than not kills you in a silly way ... which is great for a change ;)

For me it's up there with Morowind and Dark forces II , before Fallout 3/new vegas, unreal and half life. An earnest recomendation ;)