Choose whatever your wallet can afford or whatever you have around. That Raynox looks interesting and has decent reviews. Might order one to see how it performs with out of camera images.
Here are some pics from various lenses with and without attachments.
Tamron 90mm f/2.8 Adaptall manual focus macro lens (picked up for ~$200 via eBay).
Nikon 18-70mm f/3.5-4.5 (not a macro lens...)
Nikon 105mm f/2.8 (non-VR)
Nikon 55mm f/3.5 micro
Size of the fw limpet next to tip of a Bic pen to show relative size.
Nikon 60mm f/2.8 macro
Nikon 50mm f/1.4D (another non-macro lens)
Same lens, but reverse mounted
105mm f/2.8 VR at 1:1
105mm f/2.8 VR at 1:1 with Kenko extension tubes
Baby mysis at ~0.25"
105mm VR @1:1 + all three Kenko tubes stacked
105mm VR at various magnification
Samsung Galaxy Nexus (cam phone for kicks