I recommend Guild Wars, a midieval MMORPG that can be found in your local Walmart, Gamestop, etc.
Unlike WoW, it features no subscription fee. Just buy one of the three main games (Prophecies, Factions, Nightfall), get an internet connection, done.
The game has 2 modes- PvE (Player vs. Environment, effectively campaign) and PvP (Player vs. Player). A character can either be made for PvE, in which you team up with other players to get through the game's story or for PvP in which you can enter one of many competitive gametypes. A PvP only character starts out at the max level of 20 with max equipment for free but cannot be used for PvE, whereas a PvE made character starts out at the minimum level (1) and must be raised but it has much more armor options for people who love to pimp their character's appearance, such as myself, and can also be used in PvP.
As previously stated, there are 3 main games. Prophecies is the first game, which provides you with the ability to play as the 6 core classes (Warrior, Ranger, Elementalist, Necromancer, Mesmer, and Monk). Factions is the 2nd game that is set in an Asian environment and provides the 6 core classes plus the Assassin and Ritualist. Nightfall is the 3rd game that is set in an African environment, sports the most challenging PvE of the three, and allows you to use the 6 core classes plus the Paragon and the Dervish. There is also an expansion, Guild Wars: Eye of the North, which simply provides additional skills and PvE options. To play EotN, you must own one of the other 3 games.
The game sports 10 classes:
Warrior (Core)- A straightforward tank that uses one-handed swords, one-handed axes, and 2-handed hammers. Also possesses tactical abilities, such as stances and shouts. Primary warriors possess great strength, which adds to their tanking and damage dealing capabilities.
Ranger (Core)- A survivor equipped with a bow as the primary weapon. Can tame animals, set traps, and apply the benefits of nature to combat (such as applying poison to an arrow). The Expertise attribute of primary rangers reduces the cost of many non-spell skills.
Elementalist (Core)- A mage with the ability to use Fire (for nuking), Water (for hindering), Air (for high damage bursts), and Earth (defense) magics. The primary attribute for Elementalists is Energy Storage, which increases an Elementalists energy pool and energy management abilities.
Necromancer (Core)- An "anti-hero" of sorts who specializes in hexing opponents, stealing health, and summoning undead minions, sometimes at the cost of sacrificing hp. In contrast to the mesmer, it's hexes often serve as anti-melee. Primary Necromancers have Soul Reaping, which causes them to gain energy from the death of others.
Mesmer (Core)- A unit built upon shutting down the opponent. Generally viewed as a king in high level pvp and useless in PvE. Mesmers excel at anti-caster and also provide anti-melee hexes. Definitely the most unique class in the game, as if wearing masquerade clothes in battle didn't already hint that. Primary mesmers can cast spells and signets faster than any other class.
Monk (Core)- The healer of the game. Monks can use Healing Prayers (Heal stuff), Protection Prayers (prevent damage from ever happening), or Smiting Prayers (holy damage abilities that players generally discriminate against users of). Primary Monks gain Divine Favor, which adds some extra healing to all of their spells that target an ally, including Protection and Smiting Prayers.
Assassin (Factions)- Despite being named Assassins, Ninjas is more of an apt term. This class is built around teleporting to a foe, unleashing a powerful quick combo, and then teleporting away. You might call them the ultimate coward. This class uses daggers. Primary Assassins gain Critical Strikes, which increases their chance to deal increased damage and grants them energy when they land a critical hit.
Ritualist (Factions)- An unorthodox class. They are capable of summoning immobile offensive and support spirits, healing people with spiritual power, and getting powers from the ashes of long-dead heroes, as well as smiting foes with spiritual lightning. Primary Ritualists can summon creatures with much more health than any other class is capable of summoning.
Paragon (Nightfall)- This class can be seen as a hybrid between the warrior and a ranger in that it has some of the warriors tanking abilities and deals straight-forward damage, but it does so by chucking spears from a distance. The Paragon is a master of buffing allies with widespread shouts and chants. Primary Paragons can energy depending on how many allies are affected by their shouts.
Dervish (Nightfall)- The Dervish is a scythe wielding wanderer who is close to the 5 gods. He is so close to them, in fact, that he can use holy enchantments and powers and even become a physical representation of any of the 5 gods, getting powerful temporary buffs as a result. Only primary Dervishes can make good use of the god forms, and they get the added benefit of gaining energy when an enchantment on them ends.
The class system in Guild Wars is dual-class. Each character is capable of having an unchangeable primary class (the class you created them as) and a changeable secondary class. The primary class effects the character's energy pool, energy regeneration, armor type and effectiveness, as well as their primary attribute. Secondary classes grant the character an additional set of skills and attributes, of course not allowing your character to use the primary attribute of the secondary class.
Guild Wars is often seen as a low-grind game, due to its low level cap that can literally be reached in only a day (or even a few hours in the case of some), the ability to make a PvP only character, and the optionality of all grind-based elements, such as titles and prestige equipment. True to its name, Guild Wars focuses around the ability of a player to form Guilds (groups of up to 50 players bearing the same cape, Guild Hall, Guild Name, etc.) and Alliances (groups of up to 10 allied guilds). This, along with the game's intuitive chat system, make it perfect for your socializing needs. It certainly doesn't hurt that it has truly spectacular multiplayer, with many different modes accomadating both noobs and pros alike and only costs as much as the games you are willing to buy for it.