Recs.
Updated
Diablo III is an action RPG that supports 1-4 players developed and published by Blizzard Entertainment.
SpecsUpdate
Pros
Pro Heavily focused around customization
About 30 activated skills per class, 5 unique runes per activated ability that modify how it behaves, and randomized gear that can further change how your character plays.
Your playstyle might dramatically change based off of how you want to cater to your team, what abilities you might have just unlocked, and whether or not you want your goblins fried or diced.
Pro Decent selection of character builds to try out
There are more than 50 distinct class/skill combinations, including ranged builds, melee builds, support builds, defensive builds, pure-offense builds, and many more. You're sure to find a build that you'll enjoy playing, whether you prefer to play alone or with friends.
Cons
Con Endgame grinding can get really repetitive
The endgame in Diablo III consists of only two things – completing bounties and clearing greater rifts. Both of these have very little variation in them, so quite often you'll run through the same map layouts, clear the same enemies, and complete the same objectives. This gets extremely stale after long play sessions and can cause you not to pick up the game again.
Con Less focused around growth than previous installments
Previous Diablo games were known for having permanent improvements throughout the game, where Diablo 3 focuses more on customization as you increase in levels rather than improving your abilities. There's a chance that you will unlock your favorite ability at level 5 (I'm looking at you, Rapid Fire) and never use anything else in the game, because you can. Many people consider this an issue with Diablo 3, and expected more of the "specialist" style of gameplay.