Hey Valor. I did not know that the first girl you posted was from a game. A have an art book called Virtual Beauties 2020, that showcases high poly virtual Idols. That character and similar ones to her are in there. The artist's name is Sonehati and his site is...
http://www.polygons.tv or
http://home.interlink.or.jp/~polygonsNow for Tifa vs Lulu. I think that Lulu is heaps hotter, but I like more villianess looking women. Keep in mind that the conceptual art is very different to how the two of them look in the games. Tifa has a MASSIVE rack at the end. My friends and I were just standing around watching the final cut scene (when it came out), with our jaws around our stomaches

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Lara. The most overated game character in history. She became larger in number two, then they started to make her smaller as they were recieving too much shit from various people. One of three's selling points was that she now had 'an achievable chest'

DoA has always had good looking, busty women in it. It's just a pity that they started dumbing down the bouncyness after DoA2

One game that I have is called Sexy Beach 2. You just pick a girl of your choice (two are very rackable), and then just watch them do crap on a beach

It's DoAX without the volleyball. You have to turn them on and then you eventually get to have sex with them. Unfortunately it kept on crashing, so I haven't got passed that part

I bought my copy from Ebay, but they have copies available at
www.suprnova.org.
Paul Steed is known in the gaming area for making girls with
1. Largish breasts.
2. MASSIVE armoured boots.
He did the characters for Quake 2&3. A good start is the Crackwhore model he made for Quake 2. Get it from
www.polycount.com Warning. The site is a crappy pain in the arse, so just be patient.
There are some more on the top of my head, but they just wont come down to my mouth. Damn it.
I don't really know if showing hentai images of game characters really counts

They make EVERY game character have big breasts. I have a Winamp skin of that Tifa wall as well if people want it.