Personally I've not read any Wuxia novels, but I can give you some obvious examples.
The aformentioned Louis Cha (aka Jinyong) is also the author The Condor Trilogy. They're probably the most popular wuxia stories ever in Asia and have been adapted numerous times as TV series and even anime. They are:
The Legend of the Condor Heroes 射鵰英雄傳 (1957)
The Return of the Condor Heroes 神鵰俠侶 (1959)
The Heavenly Sword and the Dragon Saber 倚天屠龍記 (1961)
Another great example is Crane Iron Pentalogy by Wang Dulu. But why this particular series you may ask? Well, the fourth book in the cycle is Crouching Tiger, Hidden Dragon, which as everyone knows was adapted for the screen by Ang Lee in 2000 and became a huge hit. Unfortunately none of the books are available in English, and I don't know if anyone has taken the time to translate them online. The books in the Pentalogy are:
Crane Frightens Kunlun He Jing Kunlun 鹤惊昆仑
Treasured Sword, Golden Hairpin Baojian Jinchai 宝剑金钗
Sword Force, Pearl Shine Jian Qi Zhu Guang 剑气珠光
Crouching Tiger, Hidden Dragon Wo Hu Cang Long 卧虎藏龙
Iron Knight, Silver Vase Tieji Yinping 铁骑银瓶
As for novels about the Samurai, I'll second CCamfield's recommendation of the Musashi books. They may be a bit dated but they're still enjoyable nonetheless. But one story I think that deserves to be mentioned is Lone Wolf and Cub. Even though it is a manga series rather than a novel, it's still one of the best written series about feudal Japan ever published. Seek it out if you can, all 28 volumes are available in English from Dark Horse Comics.