Serato is the best choice for professional DJs.
It's Very easy to learn how to use it: the display can be changed in the way you prefer and there are multiple options, and that's a good thing because everyone can work in the most comfortable way.
There is also a great playlist manager that allows you to create your folders inside the software and which are linked to your profile, so you don't need to have the folders in mac or pc that you are using (but of course you need the songs so the computer can find the files he needs).
The FX section is user friendly and gives you the possibility of manipulate your effects, but most of all...THEY SOUND GOOD, because they don't ruin the sound of your mix like in other softwares with a 100% wet signal once you set them ON.
Cue section and loop section clear and smooth, I love that you can rename your cue points and give them different colours.
The only parts that are more complex to use are the sync mode and the beat grid, but with some practice they can be handled easily. Settings are very detailed and adjustable.