This is a common question for people who are interested in picking up a new instrument. There are some definite benefits to both. If you are just starting out and you want to learn in an inexpensive way, then typically the acoustic guitar is the best choice. Acoustic guitars are self-contained, meaning they need very few accessories. As long as you have a solid hard case to tote the instrument around then you are good to go. In addition, you will not have to purchase an amplifier, chords, or foot pedals.
Another factor to consider when deciding what kind of guitar to purchase is the desired use of the instrument. If you are considering joining a band some day then perhaps you should take the early plunge and buy the electric guitar. If rock stardom is not in the cards for you then the acoustic is the obvious answer. It will allow you to be more mobile, in that you will be able to take your instrument with you to college, to church or the campfire. It really comes down to a personal preference when it comes to what kind of guitar to buy.