You can either go with a 35mm or 55mm f1.8 fixed focal lenght lens (plastic fantastic). Fixed focal lenght lenses will give you very sharp images but the downside is that they can't zoom.
Or you can go for a 16-85mm f3.5 - 5.6 witch will give you a nice zoom (not too much) and a awesome picture! Its a bit more expensive but thats how it goes.
All three lenses are nikkor lenses, I don't have experience with other brands yet.
That said, I would go for the D3300 + better lens.