The best- not one of the best - the BEST nursing student in our class almost passed out in her operating room rotation. This girl gets the best grades, has excellent bedside manner and has the most varied experience dealing with all kinds of patient care. She just can't handle the OR.
If you really wanna gut-check, though, go get a job at a nursing home. I remember when I was first trained in as a certified nursing assistant, I was a little squeamish, too, but when you're following around a busy senior CNA that's training you in, you almost don't have time to worry about the gross-factor...you're trying to make a good first impression. When she says, "Go pick up that dirty diaper and toss it with the linens!" you just do it. I remember they told me in training that after working as a CNA for a while, I'd be "eating a my lunch in one hand and changing a poopy diaper with the other." And that was pretty much right on the money
Maybe before you go running out to get a job, though, go through all the forums here and read a lot of the stories. Save the forum entitled, "What's the Grossest Thing You've Ever Come Across?" (or something like that) for the end, though.
I should also mention, that if you decide to pursue your bachelor's degree right away, you could go straight from school to a very well-paying desk job in the nursing field.