A good lens for Nikon D3100?

I have a Nikon D3100 and it came with a standard Nikon 18-55 mm. Is there a lens that's great for everything? Like macro and long shots… Macro is very important!

Can you recommend a lens that is cheap as well?

There are no lenses that are great at everything. One of the best lenses for general use is the Nikkor 18-200mm VR lens, which retails about $750-800. For a macro lens, the 60mm 85mm or 100mm lenses are all good. The cheapest is the 60mm macro

http://www.bhphotovideo.com/...200mm.html
http://www.bhphotovideo.com/..._2_8G.html

I suggest Sigma 50mm f/2.8 EX DG Macro Lens for Nikon SLR Cameras,
Bought this lens to assist in Small Product Photography. Since depth of field is normally limited in Macro Photography, the ability of this lens to stop down to F45 was crucial. The result was fine detail and color reproduction to the point where I could see my finger prints on the bezels of the watches. Got to wear cotton gloves!

Read 51 customer reviews in below site

If you are really into macro then I would spend the money (475.00) and get the AF-S DX Micro NIKKOR 85mm f/3.5G ED VR. It is also the only DX format macro lens that Nikon makes. If you don't want to spend that kind of money then I have taken many beautiful macro shots with the Normal zoom, 55-200mm and its only 200.00.It is not a true macro lens but gets the job done. I will leave some you a link to my flickr where you can see the results.