Jurassic park Gift edition. It had a tipped in "signature" page and was advertised as "Signed edition". A whoops moment for the publisher. I owned one and sold it on ebay years ago-with full disclosure. It was a gorgeous "reproduction" of Crichton's signature, done in blue pen ink (at least that is how it looked). Also had a glassine page preceding the signature page (or perhaps it was the book wrapper-memory fades on this one).
Edit=Yes, it had the clear acetate cover with a t-rex etched/printed/lasered on it.
Thanks to mulleins.