Hehehe... Gamespot quote taken from Soldat Homepage. Soldat definitely IS the best if you ask me. I used to play it multiplayer-ly online once or twice while studying in the UK back then, but I would usually enjoy more playing it offline, alone. Why? There were (and definitely ARE) some seriously sick people killing for fun out there. I just couldn't (and still can't) survive :P
Some screenshots, also taken from the homepage, in case you guys are not interested enough to go there yourselves:
It's fun, it's addictive, it's crazeee(!), and it kills time too. Blood and explosions all over. Can't say more. Try it yourselves. Even the free version is more than enough to satisfy your bloodlust. Hehhh. After all the download size is only 13MB or something. That's actually very small for such an action-packed game!