Interesting question, but the better question would be how many games do you see yourself buying during the life time of the PS3 and how many do you see yourself playing throughout that entire life cycle?

Game installs and saves would be the bare minimum stored on a console, but once you step up to using it as a media player/hub, there really isn't such a thing as "too much space."

On PC, I'm eventually going to have to step up to a 1TB drive, just to keep my Steam purchases installed on my boot drive, even though it is not used to store all my media.

you mean optional instals or those games that you have to instal?
games with instals probably way over 150GB since there's like 40+ ps3 games that automatically instal 0.5-5gb.

It has to be a lot higher than 150GB.

I kind of stopped paying attention to install sizes after swapping drives over a year ago, but I would think that it would be quite a bit higher.

Going by the box jacket required space, the 35 titles I own add up to roughly 31GB of combined game install space. Of course this doesn't include patches, updates, additions, game save data, etc. And I know that the game data on many of the games I own is considerably higher than the "minimum required space" as listed on the box jacket.

Since the PS3 library is significantly larger than 150 titles, just going by averages, it's a lot higher.

InFamous - 1301 MB
Haze - 3819 MB
Gran Turismo 5 Prologue Spec III PAL - 6325 MB
Ratchet & Clank Tools of Destruction - 363 MB
Resistance 2 1.6 - 663 MB

im pretty sure Eye of Judgement is the biggest.

Instal size for this one depends on whether you bought BR release or PSN release. But i don't know details.

 More than 200gb, less than 550gb.

Most likely between 90GB - 130GB

so does most of the ps3 games have some kind of mandatory install? i'm not talking only about those 2-6gb ones but also those 100-600mb.my friends who have ps3 40gb and 80gb versions have already full or more than 2/3 of hdd space taken by installs.

this is wrong

4.6GB is the total