If real image quality is your main concern, then I'd buy the XTi and a better lens. The XSi does have more resolution and overall better image quality. But that won't make better pictures. Practice and good technique make good pictures. And it doesn't hurt to have the best possible glass in front of your sensor. The kit lenses are ok. But better lenses make a real, noticeable difference. Tell us what you want to take pictures of and we can make some lens suggestions for you