I currently am playing an old-school styled MMORPG called Tibia. I've played since about 2002, and ive seen the game grow and change significantly. Most people take 1 look at the graphics and walk away, but it really is a great MMO.
Pros:
1. No level cap. Period. I believe this alone makes Tibia a great game because it allows players to actually be the best in the world. Most people that play are below level 100, with the highest level in the world being above 500.
2. Actual PVP. This also makes it a great MMO to play. If you don't like someone, you can kill them. Not only do they die, but they lose experience and even possibly some items. This creates an extremely satisfying moment on either side. Ive survived a few PK attacks and believe me, my heart is racing because i know what is at stake. There are safe areas obviously, but killable areas cover about 95% of the game world.
3. Death matters. You don't just respawn and act like nothing happens. You lose EXP, possibly levels. This can be minimized with in game enchantments. You also lose items. (this can be prevented with an amulet that prevents item loss.
4. You don't have to play on a PVP world. You can choose to not be able to pvp at all, have it as optional, or even have it enforced - you get experience for killing players higher level than you. This last option i have not seen in any other game that also has high penalties for death, which makes these worlds for hardcore players.
5. Its free. And i don't mean "congratulations you advanced to level 20, purchase a subscription to advance farther" free. I mean that you can experience the game forever and never pay.
6. Payed accounts are beneficial, but not needed. You have a choice to pay which grants: Access to new areas, new spells, new quests, and new outfits for your character.
7. Bosses. Bosses in this game are hard. They appear in the game world sparatically, with a world message to all players online. The world then has a day to kill them and recieve the rarest equipment possible. Top players on the server come together (sometimes rival guilds will even fight over bosses when they spawn) to bring them down. There is no such thing as a "routine" boss in Tibia.
8. Raids. Cities will sometimes be attacked by monsters that spawn outside the walls. sometimes this is as simple as rats, but can be as dangerous as orcs or undead hordes.
9. Houses. Yes, you can purchase your own house to showcase all your armor in to other players. These can only be bought with a payed account, but are seldom seen in other games.
10. Guildhalls. Your guilds can have their own houses, which are roughly 5-10x biggere than an average house. Again you must be premium to buy one.
Cons:
1. Graphics are certainly not that great, but definitely not horrible to look at. I will post a screenshot or two.
2. 4 vocations. This is not necessarily a con, but there are only 4 classes to choose from: knight (melee fighter), Druid (healing mage), Sorcerer (offensive mage), and Palladin (ranged damage)
3. Players from all over the world play, in their native language. Consistantly you will encounter people that speak no word of english and only brazilian (the game is a hit in brazil), portugese, or swedish.
4. Bots. sadly, it is possible for people to cheat at the game and have their computer play their character in hunting areas to level for them. This is not a game-breaker, but can be annoying.
Obviously I am a little biased because this was the first MMO i ever played, and i base all others on it.
Screenshots:
