Honestly, I'd love to have things added to my small but current JP collection. Anything that the previous people mentioned are awesome ideas.
10,000 volts sign would be awesome (as someone mentioned)
definitely a card game (collectibles and whatnot)
Concept Art book (you can bet your a$$ i would get that)
(as mentioned by me and other people) Barbasol can
Upon release on CD: a collector's edition featuring a "making of" dvd
Map of the island is also a sick idea
Muldoon's park warden vest
a small replica of the fighting dinosaur skeletons in the visitors center (if possible :P)
dinosaur icons (like the skeleton parts that identify which dino is located where on the island) check the attachment if you arent sure what im talking about.
so yeah any of these things ^ or anything that other people mention would be sweet