The first Vernor Vinge books I read were A Fire Upon The Deep and A Deepness In The Sky ... not surprising, since they're the most famous, and also the best. I was a bit disappointed by Rainbows End. Just recently I read two of his earlier novels (written in the 80s), The Peace War and Marooned In Realtime --- the latter being a sequel to the former --- and I think they're excellent, perhaps not as good as Fire and Deepness, but Marooned in particular I found more intriguing and even quite moving.
Warning: if you haven't read these books, go out now and read them before you come back to the rest of this post, because spoilers are ahead...
Marooned and Rainbows End present two rather different visions of human development, and Rainbows End is far closer to my own thinking even though I like the book less. I'm ignoring the bobbles here --- they're a wonderful plot device, but I think the real themes of Marooned are the technological Singularity and a yearning for anarcho-capitalism. At heart I think Marooned is fundamentally an optimistic view of human progress to the Singularity. Rainbows End, on the other hand, seems to me to be a much darker view, a view of humanity lurching from one potential planet-killing catastrophe to the next at decreasing intervals, with no Singularity-salvation in sight. Now, Vinge may make a liar of me yet, since he's said he'd like to do a sequel to Rainbows End, but based on what he's written so far I guess in the twenty years between the books he's become more pessimistic. Although curiously, he may have become a lot more optimistic about governments --- in Marooned he hates governments, in Rainbows End we see a benign totalitarian state.
Personally I think Rainbows End is too optimistic :-). I wrote about this a while ago and I stand by it: the technology that could eventually lead to some kind of Singularity (very eventually; this stuff is way, way harder than most techo-futurists imagine), leads much sooner to either the total elimination of cognitive freedom or the destruction of all intelligent life. It's just not realistic to imagine we can walk the ever-thinning razor's edge for long. Man is fallen, but he still has a long way to fall. God is going to have to save us from ourselves, again.
Time to stop. Excessive futurist navel-gazing is definitely a sin :-).