I honestly think that this is the best superhero system I have ever come across.
It's brilliance lies partly with the ORE (One-Roll Engine) system itself, which is a fast and simple system based on rolling a number of d10 (up to 10d10) and looking for matches. In most cases, one roll of the dice determines everything from initiative to hit location to damage, and only in certain cases will you have to make more than one roll per turn of combat. Everyone I know has found it easy to learn and easy to use.
The only complicated part of the game mechanics is power creation, but this is also where Wild Talents absolutely shines. There is a very comprehensive list of ready-to-play superpowers to be used both as written, and as base examples to modifiy for individual taste. They are also good examples of how powers fit together - useful when you are building your own.
Powers are build with one or more of three basic power qualities (Attacks, Defends and Useful) which determine what you can do with the power, and to each quality you can add extras and flaws for added effects, limits and perks. Most of it is pretty easy to understand and self-explanatory, but there are certain parts that take a little effort to get the hang of. However, using this system you can create any power you can think of - and I mean that literally! I have yet to come up with something that can't be designed using the system.
This book contains the complete rules you need to play, including a section with modern day NPCs, a small selection of Animals, and a few sample characters - three of which are used in the book's example play.
Wild Talents can be a quite lethal game, though - it is more gritty than four-color, but the book contains several rules options and suggestions for tailoring it to different styles of play.
Because of the total freedom in power creation, there is very litte inherent game balance. In fact, some places in the text actually encourage min-maxing the system for such imbalance and think outside the box when approaching challenges. There's a three-page chapter on different approaches choose and how to get them to work. As such, the game requires a bit more co-operation between GM and players than many other games.
If you think other super hero games are a bit too limited in their choices of powers, and you want an easy to learn, fast paced combat system that can easily be tailored from realistic to four-color, then this is the system for you!
There are also several different setting books published to date (most of them even come with a free pdf of these rules!), most notably a victorian setting, a civil war setting, and two alternate history 20th century settings; all of them well worth checking out.