i thought Earthworld was pretty good. took a while to get used to the author's style, but i liked it. i may pick up Dreams of Empire tomorrow since its part of the 50th line.
For the hell of it, my opinions on the 50th line.
Ten Little Aliens is really difficult to read, especially the chapter where it all goes Choose Your Own Adventure.
Dreams of Empire is pretty cool with political intrigue and an awesome battle.
Last of the Gaderene is awesome and great fun in the Pertwee era.
Festival of Death is okay. Think of it as a Moffat script written a decade early.
Fear of the Dark isn't so great though it does have some interesting guest characters.
Players is awesome. The Sixth Doctor on an adventure with Winston Churchill. Lots of historical stuff tied into this one.
Remembrance of the Daleks, meh. Might as well just watch the episode, the novelization doesn't really add that much.
Earthworld is okay, though I suspect it might mean more if I were familiar with the Eighth Doctor's novel continuity.
Only Human is good but not really memorable.
Same with Beautiful Chaos, although this does provide more insight into Donna's family and Wilf.
The Silent Stars Go By as mentioned above as awesome. Ice Warriors rule!