The Saxon Chronicles by Bernard Cornwell; stumbled upon it while on holiday in central Australia. The series is about anglo-saxons in the dark ages, an era not comprehensively recorded (hence the name), and it's violent protaganist's involvements and interactions with the few known historical figures of the British Isles at the time. A lot of that boils down to cracking good swordfights and the vividly described brutality of man in a nigh to lawless era. I've been quick to buy books from ol' Bernard ever since... but i'd not recommend it for reading to your children.
Assassin's Apprentice by Robin Hobb, bumbled into in my uncle's library some years ago. An enjoyable read at the time which i'd recommend for teenagers particularly, it gave a different take on men and magic to most fantasy novels.
The Black Company by Glen Cook, a gritty and modern-influence fantasy series which can feel amateur at first, until you realize the prose is deliberately of such a nature as the warrior-scribe protagonist would use in his chronicles. It feels like a soldier talking around a campfire, feeling his oats after a drink; unevenly educated, mixing with a tough bunch of malcontents, handling problems very personally. I'm not sure what experiences Glen called upon to write it but the stories have a distinctive and edgy feel in the telling.
I would have said Starship Troopers by Robert E. Heinlein, but I've a suspicion someone recommended it to me (can't rightly say). A pity, because it's an awesome read; comprehensive and highly influential to the scifi genre. Perhaps appropriately, that one started me on science fiction.