All but the second will be very bad for gaming, and none of them are very good deals.
No. 1 - weaker CPU than I'd like to see in a gaming rig, very weak graphics card, motherboard with limited expansion options, low PSU (no brand shown, probably bad quality), bad case.
No. 2 - slightly better case, slightly stronger CPU which has been overclocked (possibly a bad point, if you're planning on overclocking you probably want to do this yourself rather than trust someone else), much strogner graphics card which is fairly good for today's games, PSU with more power but I've never heard of "KingWin" so probably not a good brand.
No. 3 - much better CPU than any of the other computers listed, again a weak graphics card, choice of operating systems, again no PSU mentioned.
No. 4 - free sculpture (?), extremely weak CPU, very old motherboard, weaker graphics card than I'd recommend but better than nos 1 and 3, only 2GB RAM vs 4GB for the others, lots of cooling but it might be loud with 80mm fans, better rated PSu than nos 1 and 3 but again no brand listed.
saint_hades, if you can support your advice to buy Alienware, I'd be very interested. My own advice is to steer way clear of them unless you have a lot more money than sense.
mattman, what's your budget?
Also, topic moved to hardware so it will get more attention from the right people.