Reddit reviews Numenera Corebook

Numenera is a hot new RPG by Monte Cook (of 3.5 D&D fame) with a unique setting. Essentially it's a science-fantasy game set far enough in the future that civlization has returned to a medieval state, but high-tech ruins are still lying around. I can personally recommend it as being easy to learn and fun for all styles of play. It's also very very easy to run (GM never rolls dice, just sets difficulties for the players) and I'm having a blast running my current Numenera game.

here some reviews. Looks like some love it, some didn't

http://www.amazon.com/Numenera-Corebook-Monte-Cook/product-reviews/1939979005

I usually recommend the Cypher System by Monte Cook for new players (it comes in multiple flavors: generic, future-fantasy, dimension-hopping secret agents, and American Gods-ish). Like D&D 5e, it's a middle-of-the-road game which is open to a lot of different playstyles. It has straightforward rules (simpler than D&D 5e) that can be adapted to whatever setting your players are most interested in (space opera, fantasy, superheroes). Character creation is very easy to follow, and much quicker than D&D.

Fate is another option, although it might be a little confusing if it's your first RPG. Its rules are simple, but the complete lack of constraints on players and the DM might be a little overwhelming. Its rules are also fairly unorthodox, so it won't be so helpful if you're interested in eventually trying more mainstream games.