My holy grails would be, the source code to H3 but thats a long shot. Star Wars Battlefront 3 PC any build (I know Free Radical had one)
Let's see here... The Gameboy Color South Park game Alpha builds of Grand Theft Auto III XBLA remake of Goldeneye Demonik Fear Effect: Inferno Croc 3 Dinosaur Planet Twelve Tales Conker builds
Definitely Resident Evil 1.5, the thing that made me obsessed on the BETA and Prototype scene since my Junior High years.
Is there anything rarer than the SNES-PlayStation? I've been trying hard to think of a rarer or more legendary piece of gaming hardware/software and I honestly cannot come up with anything else. It might just be the absolute rarest item in all gaming. -doulomb
Link to the Past on the Famicom before it became an SNES game, Final Fantasy 4 same thing... probably lots of examples of one-of-a-kind items hidden in company archives that no one will ever get a touch at. The fact stuff like Shenmue Saturn have no confirmed copies yet now this SNES CD proto has an officially confirmed one kinda takes it off the list of absolute rarest of all time.
I doubt anyone would pay more for a copy of Shenumue Saturn or any of those other games than the Nintendo Playstation, which was my point. -doulomb
Most expensive does not mean rarest though There are probably a few known items, and likely several unknown, that would sell for a disgraceful price too...right item to the right buyer of course... (As an aside, I would certainly pay more for Saturn Shenmue than I would for a Nintendo Playstation...but I know what you mean in general terms...) Me, I'd love a Taito WoWoW, so many fab Taito games from the mid 80's and following. Edit...unreleased, silly me, at least one of the three was.
As a huge fan of the wipE'out" racer series, I would LOVE to see the work on the cancelled PS4 game be leaked/released. Also, Liverpool's mocap project that they were working on.
IIRC, some people said that the 80% done of RE 1.5 was probably an unlikely estimate, however, in one of the IMAC Wesker videos, it's stated that the cutscenes were already complete, also i've read somewhere that capcom had already an minigame based on the Battle Extreme done for the game. For me, the missing 20% was around the minigames, and judging by the extracted backgrounds from the RE2 trails and beta, a few lab ones. But now, it would be interesting for me to see the development of the final version of RE2, the earliest thing I do know is some proof of concept backgrounds from the streets, dated around the time the RE 1.5 got scrapped.
I knew about the completed FMV sequences, but I'd love to see more information on the minigames that Capcom was planning, as this suggests development really was in the final stages. However, I'm not sure about your estimate of how complete the backgrounds were - apart from the streets already being redesigned before the 1.5 concept was even abandoned, wasn't the sewer area undergoing another overhaul at the time? I seem to recall a timeline comparison suggesting there were four distinct eras to this part of the game, which may explain why not much was shown of it even in the Complete Disc footage. Also, wasn't it once claimed that most of the remaining 20% or so would have been for bug testing and to implement voice or video files where these were necessary? Either way, that last build would be fantastic to own, as I suspect it can not only be played from start to finish with both characters, but could quite easily be finished by a team such as IGAS with little guesswork or reconstruction necessary...
I have a prototype cart for Obscure Aura on the DS. It was never released because Hydrovision Entertainment were having budget issues. The cart is simply labeled as "Obscure Debug" and it only runs on hacked or debug DS systems. This debug/proto only allows you to run around a series of connected rooms as one of the zombie monsters from Obscure 1. Its far from complete. Id release it myself if I had a way to rip DS carts.
@cammers1995 if you have a NDS Flashcard you can rip the contents of this cart relatively easy. Check this thread (halfway, wifi ftp dumper) http://assemblergames.com/l/threads/ripping-your-own-ds-games.15540/
Want: Any pre-release version of Warhawk PS3 (Press event release / Campaign demo). On a side note, there's a half-built version of Warhawk for the PS2 float somewhere on the Interwebs. That's something I'd like to get a hold of. Have: Warhawk PS3 promotional copy. (Some slight differences with the retail version.) Warhawk Press Kit
I would like to nominate any tools for working with Elder Scrolls: Oblivion, Fallout 3, Fallout New Vegas or Skyrim that Bethesda has internally but hasn't released (for example Bethesda never released any art tools for these games for some reason)