I think this is probably a bit more on the girly end of things, but I've found that taking good care of myself (when possible of course) in hospital helps keep my morale up. I think the sicker you look, the sicker you feel, so if you have the energy it's worth making a little effort. I bring my nice robe so I don't need to wear the hospital gown, my favourite perfume, and my own shower stuff in little bottles. I bring a tiny bit of make up so that when people visit I don't need to deal with them telling me how tired I look (I'm in the hospital, duh!) Bottom line, having your own things makes everything feel better. Of course, post-op and such things like this don't really matter, but I figure then you're so zoned out it hardly matters! But when you're hospitalized, nothing beats being able to wash your hair and feel presentable.
My mom started buying me a stuffed animal every time I got hospitalized when I was diagnosed at 11. She still does this when I'm 22 because she's the best. This past time it was Tigger. It's nice to have something to hold, especially if you're stuck sleeping in a position you aren't used to (despite how juvenile it may look!) And bring your own pillow if you're counting on being there for a while! Hospital pillows SUCK! Ugh! Also, I've never brought an eye mask before but after my past hospitalization I see the necessity! Every time my roomie's lights went on, I woke up and had so much trouble getting back to sleep (after an IV drip of gravol and an ativan, no less), and every time I said "I wish I owned an eye-mask."