Does anyone know where I can find a list of them? - I've been playing Survival tons, but haven't managed to get the achievement and I don't know how many different items I'm missing. Is there a list of them anywhere on the game, as in previous DOA games?

There's no need for a list because there are only 2 rare items: Xbox prototype and Xbox 360. Getting your hands on these is very difficult because they only appear seemingly once a week. You don't have to get both in the same fight. Just keep at it.

OK, thanks - I've got the prototype but have yet to see the 360, so hopefully that should do it

Oh, does the acievement apply to both single & tag survival?

yeah, it applies to both. there is no way to see what you have unforunately. basically, there is the common items that you don't have to worry about (you have them), then there is the hour glass and slotmachine (you will probably have these, but they are kinda rare, they make a funny noise when they drop), then there is the prototype xbox and the xbox360. i have heard that using differant characters help as differant characters have differant drop probabilities

the xbox 360 is awesome
its worth hella points

appear once a week? what day and hour?

Still haven't got it I've put in a few hours today and each time I get to around 40 wins. I have always been taking Jann Lee and Christie, so I may change character and see if it helps.