The Good: Gorgeous art style, some of the best pre-rendered cut scenes I have ever seen, more loot than you can shake a stick at, varied environments, awesome enemy designs, some tough bosses, lots of replay value, Auction House can be a second income
The Bad: Level layout can get boring and tedious, some poor difficulty balancing, game needs to be constantly connected online, requires dedication to get the best loot, loot isn't all that great until higher levels
Diablo III is one of the most long-awaited games in history. StarCraft II and Duke Nukem Forever are in the same boat, but Diablo III is something else. Everyone who played the last two games were either in high school or college at the time and are now in their 30's and 40's. 12 years in the making with so much turmoil and history to write a novel about. Now that the game is finally out is it any good? Blizzard surprised us with StarCraft II and how good that game is, but can they do it twice in a row? The answer is yes. The game has its fair share of problems, but they were mainly during launch with a plethora of glitches, balancing, and server issues. Most of the major problems have been patched now so I won't spend time complaining about that because I didn't experience any issues apart from the occasional server error.
The story in Diablo III is fairly good, but only people who played the last two will truly appreciate it. I found the middle of the game to be pretty uneventful, but the ending was great with a few plot twists. You play as one of many hero classes who is trying to stop the Prime Evils from taking over the world. Not just Diablo, but Azmodan, Mephisto, Belial and many others. One of the best things in the game are the many different locales from indoors to outdoors. The art style is absolutely beautiful leaving you with plenty of great scenery to look at.
Of course a dungeon crawler isn't one without a lot of loot and Diablo III has an endless amount. The best loot is at higher levels (60 is the cap) and on Nightmare difficulty. This is really a game for people who want loot. You can blow through the story and reach around level 30, but it will take another play through to get the best loot. Why do you want this loot so bad? To sell in the auction house for in-game gold or real world cash. That's right. Cash. People can bid on it or buy it outright, but don't expect anyone to bid on the crappy stuff. Only level 60 loot is really being fought for. I tried selling dozens of rare items throughout my play through and only sold one for $1.25. Really sad.
The best loot comes from bosses which are highlighted in gold. Main bosses give you the best stuff, but they can be tough as nails. Some bosses were pretty easy, such as mid-level bosses or blue sub-bosses. There were a few that just kept killing me, but I didn't die all that often. The penalty isn't very severe with just 10% durability of all your equipped items taken away, but you can always repair it at a town center. One thing I didn't do hardly at all was buy items. I always found the best ones as drops rather than at shops. I didn't even craft any items really which is a shame. I found this to be sorely wasted. I did like the new gem ability which will raise stats of items significantly. Weaker gems can be crafted into more powerful ones as well.
Of course you can take a buddy with you, but you really don't have to. This is only recommended on Nightmare difficulty, but most people will probably want to take a long break from the game and come back a few months later where the game feels a little more fresh. After I finished the game I felt I needed a long break because you are just clicking around madly while using 1-4 keys for your attacks. I sure wasn't disappointed here because there are plenty of abilities to learn; I just wish you could hotkey more of them instead of just four. I even wish there were some better AoE attacks because the last two acts throw a ton of tough enemies at you and you are constantly boxed in. I managed, but it would have been nice.
At the end of the day you are just clicking around furiously at everything that moves and trying to find the best loot in the game to sell in the auction house. This is a game for people who are dedicated. Sure you can enjoy the single player, but if you really want to experience the way Diablo was built to be played you must continue on in a second play through on a harder difficulty. Sure the game has good voice acting, some of the most beautiful pre-rendered cut scenes I have ever seen, lots of abilities, tons of loot, but in the end this is all this game is about. Looting, clicking, selling. If you don't like that then you will hate this game.
My biggest complaint would have to be the layout of each level is nearly the same. There is a fog of war for the map and you have to discover where everything is. There may be some side quests, hidden chests, and sub-bosses, but I found this tiring and kind of boring. What's here is great, I just wish there was a little more variety. Another thing I will complain about is the game's DRM. You need to be online at all times or it will boot you and you will lose your progress. I hated this more than anything, but Blizzard has successfully side-stepped pirates and I applaud them for that. Probably the only video game ever made that isn't pirateable. Other than this the game is great and well worth a purchase.