Ever wondered why MMOs always seem to make the same mistakes over and over again when they could so easily avoid them?
After over 15 years of MMO history that I've been playing through and even more of gaming history, there are a lot of things that seem to repeat over and over that I've seen. As with many things that started out small, innovation with new games has drastically decreased over the years. In the past nearly every MMO was different, had its own flair, its own mechanics and style. Today a good 90% or more of the games are clones of others.
What makes a game good .. or bad? Obviously this is a question that cannot be easily answered. A subjective topic everyone is bound to disagree on. I wanted to make a list anyways, my personal list, perhaps to give some points to think about, perhaps for others to find some games to play, maybe just to write down some thoughts because I enjoy making long winded posts, who knows

Ryn's Cooking Recipe List for MMO Ingredients:
There are so many aspects of an MMO that it is hard to pin them all down. I just write about some aspects that I can think of here, this 'list' is nowhere near complete.
<< Graphics >>
There are many aspects that make players enjoy a game, but none gives as strong of a first impression as its graphics. Many games are discarded as bad, uninteresting or the like when the graphics do not look good.
What many are not aware of however is how much not only the game world itself can influence such a decision, but also the user interface of a game. Interfaces that look like semi transparent boxes that are more of an overlay than a real interface with bland looking symbols and no real art included in the overlays, often looking as if made with MS Paint can drastically change an impression on a game and the enjoyment of playing it.
After all the interface is something that you interact with every second of the game. An interface that looks good and gives feedback to the user in a meaningful and subtle way creates a very positive feeling. If I click something I want to know that I clicked it and I want to get an instant reaction not a delayed one. This includes menu's that don't just pop up but have interesting effects to appear, buttons with click effects that go beyond just a simple sound and the like.
Blizzard makes some of the best interfaces I have seen, both for their games like World of Warcraft, Star Craft II, Diablo III as well as for their webpages and while their games might have other flaws that I don't enjoy a lot, their interfaces are some of their shining examples in my opinion that many other games can learn from.
As for the overall graphics athmosphere and a feeling that every single model belongs to the world instead of just being placed inside of it is important too. A special mention regarding athmosphere goes to the game Journey. While way too short and even though I hate puzzle games, this game's athmosphere is epic, just epic.
Many of what is often called a triple A MMO does rather well on making the gameworld and the models that are placed inside look like it belongs together and I won't go into detail here on what I think is the best game in regards to graphics. There are many that are nice be it Final Fantasy 14, Guild Wars 2 or even EVE Online in its own very simplistic way just to name a few that come to mind.
<< Gameworld >>
Players want an interesting gameworld to explore, to see something new while they are playing through the game. A world that is not adapting in any way does that only for a very short time until it becomes uninteresting. The smaller the world the harder it is for the player to see something new for long.
There are three main points that I think are important. It has to be vhast. It also needs variety and interesting things to explore.
Whats big? A very subjective thing, for me World of Warcraft doesn't have a big gameworld. I specifically mention WoW because many know it, many have played it and many more think that the gameworld is big. I feel quite the opposite, I think it is very limited. I can run through the whole gameworld from left to right (not including the Ocean) in about 15 minutes and about the same from north to south. Even less when flying. Also the Outer Regions and Northrend aren't of any serious sizes. When I'm talking of big gameworld I want to have a world that takes me hours just to run from one end to the other. Worlds like EVE Online, or Dereth in Asheron's Call, gameworlds that are so expansive that you can even after years still feel as if you're far away from having explored and memorized every single spot.
Not only is it technically possible and doable especially with all the land generating engines, but it makes exploring a gameworld interesting.
The second is variety. With manually set spawns with specific enemies (often the same type of enemy in a very small area on top of that) the exploration part is totally killed. Players find the same mob type in the same area every single day for weeks, months, years, however long till the next expansion changes the area in some meaningful way if ever at all. This is boring.
Random spawns make a game more interesting, players find some different enemy at one and the same spot, giving them more fun exploring a place. Interesting things to explore range from gathering nodes, special places of interests that give loot, achievements or whatever, dungeons and all sorts of stuff.
Many single player RPGs make it a lot of fun just exploring the area of a gameworld. Not only does it not always need a quest to go to a certain place, but going to places without quests should be encouraged.
The technology is there. Quests can and should not be linear but responding to a players choice.
Too many developers dumb down their quests too much, removing many interesting aspects for exploration. If the goal of a quest is to find a goblins head, then why do I not find a head of a goblin if I didn't meet an npc asking for it? I should have the option of finding a goblins head if I stumble upon that goblin even without talking to a questgiver first and should have the option of bringing it to him afterwards.
Did I mention that questpointers and marked areas on a map totally ruin the fun of exploring and finding things out on your own? But yes, we get to challenge of a game and dumbing down things later on.
Another point of variety is the third dimension. 90% of MMOs currently totally ignore that theres something called a hill, something called a mountain, something called an underground cave. They give players a nearly flat surface with barely any meaningful ways to climb, to jump, to fall down.
They create the illusion of an up and down but there really isn't any. Some don't have it at all and don't even give players a jump option, while other games like WoW build upon an illusion that there is a third dimension while most of their content is still flat and walking up or down is mostly a way of changing the scenery or get to another area of interest.
<< Customization and Choice >>
I want to play a melee mage who has a beard and is really thin and tall. Choices. I personally enjoy playing a character that I can customize and adapt to my playstyle and liking. Character creation is important for many players (like myself) and 5 different faces and 5 different hair styles / colours just won't do it.
I want to have sliders and want to design my own personal character. I understand that these options were not as easy to do in the past but any new MMO that even wants me as customer will need these things in order for me to even install it. There is just no real excuse not to have these options anymore in a modern game. For players who want predesigned characters, give them a few of those or even better generate a random character for them with a buttonclick.
A lot of games think it is necessary to have classes. While there are arguments for and against this I never really enjoyed being pushed into a class. I guess it's alright as long as I can still define who and what my character is. A big no go is limitations on armor sets or weapon choices. Another big no no is no customization within a class and I'm not talking about 5 choices how to adapt the character 'a little bit' and I'm definitely not talking about pure % increase modifiers which has nothing to do with adaption of a character, as it only adapts a characters stats and not the feeling of playing it in any meaningful way.
It isn't hard to have enough choices without giving the players the ability to create a character that can do everything. Melee mages while not as common of a theme as others is as viable an option to play and enjoy as many others. I seriously grow tired that I can never play those rogus with a staff, or no tankish character with a shield and a dagger and still seriously be competitive.
Not much to say here really. Throwing players into a predefined class that automatically gets certain abilities at some level not only takes out the fun of leveling up, it also makes everyone be the same ... sure thats easy for QA testing and balancing .. but also makes for a boring environment.
Games like Champions Online, while graphics and style of a Super Hero game might not interest many, has a very good character creator with near endless possibilities of how player characters look like. While it doesn't have to be this drastic and I'm not expecting the main part of the game to be its character creator, this is just one example of what a good customization of character looks can be like.