I love ubook, and use it most when I can (which is often
).
It's very configurable, and free up to the latest version (so you can still grab an older version if you don't want to pay - actually, you can still use newer versions, they aren't crippled apart from a nag screen every now and then).
If you're getting fuzzy text, make sure you have smooth fonts turned on, and fiddle with the display settings (in detailed settings mode, under fonts, set smooth mode, play with method, orientation, distribution and the two size settings). I've got a very clear display on my h1930.
Considering it's features, I think it's still a bargain at $12, and registered it straight away.
Of course, if you want to read DRM books, you either need another reader, or a little utility that's available on the net...