I myself had a "Impressive" collection at one point with everything from:
Base set shadowless to Legend awakened complete ,even had the different print numbers for the commons(3 of each per set) and uncommons (2 of each) for those sets that had them.(that took forever!!!)
All WofC promos
All jumbos
All Nintendo promos
Alll DP Promos
All HGSS to date
1st/ed ivy pikachu
E3 red cheeks pikachu
E3 yellow cheeks pikachu
E3 eon ticket sealed
prerelease clefable
Creator pack sealed
Complete sealed set of pokepark promos (individually packaged.)
Green and blue pokepark folders
yellow,green & blue pikachu collection
southern islands collection sealed
pokemon houston space center promo w/booklet
all prerelease cards (except the raichu of course) and all staff that ever came out
2008 snowflake advent calendar x2 (one opened and one sealed)
All city, state, regionals, nationals promos + staff promos from 2004 up to date
alot of the japanese movie promos
sealed japanese pikachu Lv.X package
Every worlds set from 04 -09 plus top 32, top 16, quarter's, a couple semi's and all staff cards. (recently sold all to Mr Pratte :thumb
Wolrds 2010 finalist card (sold to Mr Pratte)
Worlds 2010 quarter finalist
worlds 2010 staff
worlds 2010 set/binder
wolrds swag like you wouldn't believe x2
my most prized card that is not mentioned to often, anywhere for that matter, is the Stadium Challenge Deoxys. I mean I have alot of rare cards but to me this one is a prize as it is very limited, only 1 stadium chapllenge that year, and who knows howe many are still mint. I have seen 3 go up on ebay and 2 of those being mine. I know the guy who sold me the last one and he wants it back BADLY!!! LOL Don't get this confused with the regional championship deoxys which was massively printed.