Do you want to sterilize or sanitize them?
You may be able to sanitize your bottles in the dishwasher but you'd need to verify that it actually gets hot enough (>160) during its steam cycle to do so. I tested my dishwasher and even though it states 160 on the steam cycle, it never breaks 140. Starsan, idorphor, or properly diluted bleach are probably the easiest sanitizing options. Just be sure your bottles are clean first, regardless of the sanitizing method you choose.
To sterilize you probably have two options. Bake in the oven (340 for 1 hour, you may want to slowly raise temps to reduce the risk of thermal shock weakening the glass) or use a pressure cooker. I personally bake my bottles, but that has less to do with desiring sterilizing over sanitizing and more to do with spreading out brewing related tasks. If you put foil over the opening of the bottle prior to dry heat sterilizing, they will remain sterile more or less indefinitely.