Yakuza 5 is coming out very soon.

If you want to get into the games, look at this thread for how to emulate Yakuza 1 and 2:

http://forums.pcsx2.net/Thread-Yakuza-1-Walkthrough-using-PCSX2-including-settings

Yakuza 3, 4, 5 are all exclusive to PS3. I suggest looking here for finding PS3's cheap:

http://www.ebay.com/sch/Video-Game-Consoles-/139971/i.html?_from=R40&_nkw=ps3+console&rt=nc&LH_Auction=1

I also prefer to buy the games off Amazon:

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dvideogames&field-keywords=yakuza

I would suggest getting Dead Souls, but I'm getting the gut feeling it might pop up on PS+ sometime in the future.

If you wanna get Ishin and 6... go ahead, but the walkthroughs aren't fully translate yet.