So, for a while I played a MMORPG currently in Beta. It's called Granado Espada.
Now, technically, I can't suggest you play it. First off, downloading the client involves downloading dozens of large files, independently, from Korean servers. Second, I'm not even sure it's still operating. I think it's between beta phases at the moment. Third, you have to fill out this giant form to play... and it appears to be down.
Those are the reasons you shouldn't play.
Now let me list the reasons you should.
In terms of the standard stuff, Granado uses a typical Korean graphics suite. Which means that the world is absurdly detailed (and swanky), characters are lush (and skanky). The music is beautiful classical that fits in perfectly. The world itself is developed and unique enough to hold interest. The class system and leveling curve are solid, although weighted a lot towards hardcore players.
The game is very much a beat-em-up - there's no crafting here, and don't expect to "specialize in healing" or some such crap. No, your three characters have to be able to take on anything you encounter - running is just going to get you in worse trouble.
Why, yes, Granado lets you build, level, equip, and simultaneously control three characters. While each character is significantly more simple than, say, your Troll Shaman, together they make for a very nice change of pace and some pretty deep gameplay. Depending on who you choose and what tactics you try, the game can be a "sit back and watch the slaughter" or a "micromanage to defeat the big bosses" game.
Drops are excessively tame. You'll almost never find anything that is actually useful - no potions, no weapons, no ingredients. Some of the drops are sellable items, but most of them are the nearly-useless extremely minor instantly-effective restoratives. This means that adventuring basically boils down to a very simple equation: time and resources (bullets, potions, crystals) expended equals a certain amount of experience and gold (in form of sellables) gained.
This makes the game focus very clearly on tweaking out the strategy of your party. There's really no hunting for cool loot: all the loot is always available, if you have the cash and levels. So you can plan very far ahead and tweak which people are leveling what at what speed.
Unfortunately, they don't have the most important element: formations. There are no party formations. This is a serious problem for many types of party, including my own (two gunmen and a healer). Having to carefully arrange them individually every time a fight starts is painful, especially given the slightly dodgy AI.
Having a multi-player party is absurdly powerful. This is probably because in order to really make a dent in such a party, the enemies would have to kill off your characters in one or two hits each... which would start a feedback loop and end up killing off your whole party. Healing is obviously a dominant strategy :D.
In addition, attack types aren't as limited as in most games. For example, a gunman has a very slow reload time and no AoE, but kills shit great. My party - two gunmen - was a boss-killer party. I had an easier time against bosses than against scrubs, simply because scrubs come in faster than I can shoot and tend to pop into existence within your minimum range.
This variability lets you specialize your party in really interesting ways very different from the way you'd specialize your character in a normal MMORPG.
Moreover, unlike many other MMORPGs, you can really mix and match. For example, you can swap characters out of your party. Need the extra punch? Add an extra gunman. Worried about the swarms of scrub? Put in an elementalist. Another player in your family dying for lack of a high-level warrior? Give him yours. Yes, transfer your character to his account. Need to get someone weak up to speed? Use some XP cards on them and - poof - instant levels!
This plus tons of unlockables, hidden classes (broken, but probably being tweaked as we speak), costumes, side quests...
I won't say Granado is perfect. But I will say that it's the first MMORPG I really enjoyed.