the more RAM the better... i just got an extra 2 gb to boost it up a bit..... the settings all require the memeory, in the settings menu it display how much is used and how much total available. XP & background processes used about 500mb on mine. (think that was running a scan in NOD32 aswell)
@creator, i got to 90% i completed the story line and was doing all the other bits to get it too 100% but thats when i moved over to my online account

@also creator, yes the PC obviously would be more pwoerful than the PS3. BUT. At Rockstar games they spent quite a number of years developing this wicked game they call GTAIV for xbox and ps. Due to popular demand, it has been deemed necessary to make it for PC too. At Rockstar, they didnt want too spend a few more years making a fully 'PC' GTAIV so they just ported the PS3 version over to PC, thats why its soo bad at using hardware to its max efficiency and also why some people have been complaining about bugs etc
last 5 mins, i got this shot

attempted mugging, he found out the wrong person to mug

(bad quality, i used the print screen button

)