As for the whole crisp and sharp thing, thats really up to you, and to some extent the settings in the camera. That kit lens can actually get pretty sharp zoomed to about the middle (not all the way in and not all the way out) and the aperture somewhere in the f/8 to f/16 range. Set your camera to Av, roll the wheel behind the shutter button until you set your aperture to 11 (just a number in the middle), press the shutter button half way and see what speed it gives you. If its less than 1/50th you will need to increases your ISO, just increase one step at a time as the higher ISO’s give a lot of noise. Find a happy medium and shoot.

The first lens i recomend is the http://www.bhphotovideo.com/c/product/169267-USA/Canon_6473A003_75_300mm_f_4_0_5_6_III_Autofocus.html it’s a bigger zoom than your kit lens.
The second lens I suggest is the http://www.bhphotovideo.com/c/product/12142-USA/Canon_2514A002_Normal_EF_50mm_f_1_8.html It doesnt zoom at all, but it has an aperture of f/1.8 which is awesome with low light situations. It also is a bit sharper than your kit lens. It does these things better because it just has to do them at 50mm and not a whole zoom range.

For Macro or close up stuff you could just get one of these http://www.bhphotovideo.com/bnh/controller/home?O=search&A=search&Q=&sb=bs%2Cupper%28ds%29&sq=asc&ac=&bsi=&bhs=t&shs=&ci=158&at=Magnification_Set&at=Size_58mm&basicSubmit=Submit+Query it screws onto your lens just like a filter (you should always have a UV or sky filter on your lens more for physical protection than anything else). They make higher magnification ones as well.

Differences of the XS include:
two more megapixels
larger screen
live view
longer burst length

You can read reviews on all the Canon dslrs here:
http://the-digital-picture.com/Reviews/Canon-Digital-SLR-Camera-Reviews.aspx