dont forget guys that its not just the lens. if youve got a relatively hi res camera take a macro shot crop and resize the image so it gives the appearance that your even more zoomed in than you actually are. the higher the res, the more info, the more you can zoom in on your image...if that makes any sense? :?
A couple I took sometime ago before my camera started playing up, I think the problem with the camera is back focus or forward focus misalignement, I have some test material to find out, if so I can adjust it before I buy a new one.
These photos have no crop, just some USM and levels: