Finished (last month) one of the most ambitious and brilliant SF books - A Fire Upon the Deep by Vernor Vinge.
Although reams of well educated, intellectual criticism have been written about the book (it won the Hugo Award), let me write my two utterly insignificant lines too.
The book is utterly, overly, devastatingly ambitious. A near six hundred page epic opera, it takes the most stereotypical and beaten to death SF formulas - space operas, wicked aliens in the far, far future and adds a dash of brilliance by introducing the awesome concept of Zones of Thought - the premise being that Earth is in such a region of Universe which is the Slow Zone - faster than light travel is impossible by the laws of physics. There are other zones namely the Middle Zone and the Beyond where nearly infinite speeds are possible and ultra ultra advanced technologies and near sentient AI can exist.
The wicked aliens are undeveloped dog-like creatures who stay in packs of four or five. Loss of one member is like mutilation of a limb. Their mind is a collective sum of the individual brains and groupthink is the only mode of thinking.
An awesome odyssey unfolds in which courtly intrigue, betrayal, imaginary identities vs real identities, weird inconceivable alien beings (cf Skroderiders) play out the vision of the author in a grand backdrop of an ominously spreading Universal perversion.
The scope of inquiry and the variety of issues dealt with in this ultra speculative setting is staggering and although the book gets slightly boring in the middle, if you stick it out till the end, the reward will be supremely satisfying.
The other book which has been on the back of my mind for quite some time is The Left Hand of Darkness by Ursula K LeGuin.
Again, this is a very celebrated book and it won the Hugo Award the year in which it was published ('60s I think) but I have always found some aspects of the book to be underrated and unappreciated.
More than an SF classic which it obviously is, I found it to be one of the most touching love stories I have read. I dislike love stories and they are generally a test of my patience -whether movies or novels. (The only exceptions I can remind myself of are the movies As Good as it Gets, Eternal Sunshine of the Spotless Mind and Before Sunset). However, the love story in this book beats all previous giants.
The story is about a planet of people who are androgynous and sexually neutral for most of the year but for the short mating period (kemmer) during which, depending upon the hormonal secretions and situation encountered, the aliens (a cousin of the human race, we are told) can revert into either of the sexes.
The protagonist is an ambassador of the Galactic Federation whose task is to convince the different countries of this ultra cold, Antarctica-like planet to join the Federation. And thus is laid the foundation of a fantastic novel about the nature of wars and their connection to the sexual nature of society (the novelist seems to be of the view that since the population is sexless, the aggression latent within such a society is less than that of a 'normal' one).
The love story doesn't emerge until the later parts of the book and even then it is nowhere pronounced, as if the author did not particularly want it highlighted. But it is remarkably beautiful, subtle and heartwarming.
Ra, this post is for you. You wanted me to recommend some real badass, topnotch SF. Go ahead and get these. (Buy, beg, borrow or steal)