It definitely depends on whether or not you want to just practice silently, or have one that actually sounds nice. I assume you mean the latter
For a cheapie ($50 on sale), I recommend the Rogue Starter Acoustic. It is NOT a toy, though it is 3/4 size (I think), and for the money has a nice sound. Looks nice too, and for the price, you won't be afraid of getting it banged up.However, if you want a really nice travel guitar, I'd say get a Taylor Baby Dreadnought. This 3/4 guitar comes in standard and mahogany top, and in left-handed configuration. For $270, you can own a premium brand guitar which sounds great. Highly recommended.