7th Sea and Legend of the Five Rings got be back into roleplaying at the turn of the millennium, and the core of those rules -Roll and Keep- has been my favorite and go-to-engine since. Role and Keep is elegant, dramatic and flexible and I love it.
There are two released games that use Roll and Keep; 7thSea and Legend of the Five Ring. L5R is a pseudo-Japanese mythology setting with samurai and shugenga (wizards) and concepts like high honor and clan station. There is also a very popular L5R CCG, but I don't play it. 7thSea is a swashbuckling alternative world where the countries of Europa all reaching their Renaissance at the same time; where bloodline sorcery vie for power with the growing fields of mad science and technology.
The core dice mechanic, by which the system gets its name, is a dice-pool system with a twist. You create a pool of d10's from Traits and Skills but when you roll them you may only keep a certain number of them, adding the results of kept dice together to determine your total roll. By default the Trait score is the number of dice you get to keep and the dice from your skills are 'unkept'; this means your Traits are universally more important but are harder to raise to high levels. Skills are easier to improve and grant additional boons that unskilled characters don't get.
7thSea has Brutes and Henchmen, which are lesser NPC's, used to challenge or assist the Heroes and Villains in your games. Brutes are very simple, stats-wise, which makes the GM's job all the easier; you don't roll or track damage against Brutes, if you successfully hit one, he's out. Unfortunately Brutes travel in packs (Brute Squads). Henchmen have the same Traits and Skills that Player Characters have, are tougher than Brutes but aren't as hardy as PC's. 7thSea favors player characters as heroes. The worst that can happen from a fight is to get Knocked Out, and the GM is encouraged not to kill PC's, but instead have them wake up afterwards in captivity or in the midst of the Villain's devious-yet-subtly-flawed-death-trap.
Legend of the Five Rings, inspired by the book "Book of the Five Rings" by Miyamoto Musashi and Japanese mythology, has a different feel than 7thSea, but is no less dramatic. L5R characters are first defined by their clan, family and school of training. L5R characters start fairly similar to each other, but can quickly grow into distinct characters. L5R has two social traits for your character's Glory and Status, representing reputation and authority, which fluctuate quickly during play.L5R is a gritter setting and system than 7thSea, but glorious for all the same. If you're a fan of Kurosawa films and Japanese mythology, L5R is great. In addition, the canonical setting of L5R's Rokugan is continually evolving in response to events in the official CCG tournaments, which is an interesting idea even if it leads to occasional oddities.
I've enjoy the Roll and Keep engine so much, I am working on my own variant which is generic enough to handle just about any setting. More on this to come...