So yeah, been playing a lot of the completely Free-to-Play game called Path of Exile by Grinding Gear Games. It is an ARPG in the style heavily reminiscent of Diablo 2. This game is closer to what Diablo 3 should have been IMO.
You pick a class, play, get gear, smash stuff in hordes of enemies out to kill you. Each class has the potential for NUMEROUS builds. Every time you level (and with some quests) you get a passive skill point to put into your talent tree, which is more like a web or even the sphere grid from FFX. There are numerous paths and branches and it can feel overwhelming at first, but it's great too.
Oh and while the game IS free to play, there is NO Pay-to-win microtransactions. They do have a cash shop but everything is PURELY cosmetic outside of the ability to buy an extra tab for your chest which you really don't need, or the ability to name your chest tabs which again is unneeded. Their cosmetic stuff varies from minipets to enchant graphics for your weapons to flashy cosmetic helms to various footprint graphics.
There are NO EXP flasks you can buy, no levels you can buy, no armor you can buy from the cash shop. EVERYTHING is cosmetic, get the point? This rather unheard of and new developer have come out with the bat swinging hard and understand the concept of what Free to Play really should be.
Give them a look over at http://www.pathofexile.com/ and enjoy a completely free game that is quite fun and addicting.
Side note, when you create your first character roll in the Domination league, it has a few benefits and challenges of its own but there are the potential to get a few unique items and whatnot that are not present in Standard League, and when the Domination League ends all characters in it are converted to Standard League anyways. Avoid a Hardcore or Nemesis League though if you are a beginner as Hardcore characters on first death become Standard League and Nemesis League which is a hardcore league that grants rare monsters very very potent modifiers which can be brutal to deal with.
Enjoy the game!