I have two for my Fujitsu LOOX n560:
iGuidance by iNav which I use for US maps.
AND
CoPilot by ALK Technologies which I use for my UK/Ireland maps.
If I recall correctly, I did a fair amount of research (some of it at
GpsPasSion) and I chose these two over TomTom from what I read. At the moment, I do not remember the specifics as to why I made my choice.