So all I've ever really read is the Harry Potter series but watching Game of Thrones convinced me to start reading A Song of Ice and Fire (and buy a Kindle) and currently I'm on Clash of Kings and I'm really, really enjoying it. I think I'm going to read something else after this book (to avoid Westeros burn out!) but I have no idea where to start.
I'm not sure I want to start a new series of books so what can you guys recommend as an excellent, standalone novel? I wanted Jurassic Park but it's not on Kindle
Just off the top of my head, based on what you've read already...
Try something by Stephen King. He writes a lot of standalone books, and for some reason I think his books might appeal to someone who enjoys George R. Martin's writing. I would recommend The Stand if you want to read something big and epic, or Salem's Lot if you would rather read something a little faster. If you end up liking his books, he's written a ton, so you'll have a lot of other things to consider reading in the future.
Also, considering you were thinking about reading a Crichton book, you might think about reading something by Dean R. Koontz... He writes a lot of current-day Science fiction that is somewhat similar to Crichton's work, though Koontz's work tends to be more in the sci-horror realm. His quality varies a lot, but like Stephen King, he's written a gazillion books, and most of them are standalone. Watchers and Phantoms are both excellent choices from what most consider to be his peak period.