Wait until today and check out the iPad mini. Maybe that's your best bet.
However, if you don't have a phone and need one, then the choice is easy - go for the phone.
I need a phone and have the iPhone 5. That was my first venture to Apple products. From there I got the MacBook Pro and then the iPad. I absolutely love my iPad and use it pretty much exclusively for leisure type web surfing, paying bills, etc. I could do without the laptop if I had to give one up. But if I could only have either the iPhone or the iPad, then I would have to say the iPhone cause it can do anything an iPad can do and also can make phone calls. It's really the most versatile.