I usually don't eat it with seasonings, but all kinds of herbs can be added, depending on what you are serving with.
First off, I always use chicken broth, and I always bake it using Alton Brown's method. It's easy, hands-off, and you can use cheaper bulk brown rice, instead of the pricier boil-in-bag stuff:
If I was serving with a stirfry, I usually leave it plain, with sauce in the stirfry soaking in it really doesn't need much else. This is probably the way we use it most frequently.
For Mexican-style dishes, you can add cumin, chili powder, fresh garlic and onion, or even a little saffron.
You can flavor with lemon and a bit of thyme, and some parmesan. Put the thyme in while it's baking, add a little lemon zest tossed in at the end. Some garlic would be good here, too.