I am a big fan of hybrid character classes in any game, because sometimes you just want a switch from the traditional Warrior, Mage, Archer, Thief, Healer.

Don't get me wrong, these traditional roles are always essential to the average fantasy adventure: The Warrior tanks, the Mage and Archer deal their respective ranged damage, the Thief has either speed and agility or stealth and cunning to contribute, and the Healer is everyone's poor slave. But things really get exciting when a character class takes from a combination of these roles.

My current gaming fascination happens to be the explosively popular World of Warcraft, a game whose content is as rich as the volumes of lore it's based upon. It has, of course the five traditional character classes (known in-game as Warrior, Mage, Hunter, Rogue, and Priest, respectively), but added to these are five unique classes that, to me, combine the best of the classics. They have roots deep in Warcraft Lore and from the original real-time strategy games where their use as units defined their abilities-- very creative of Blizzard to be able to MMOify them. Also, all classes in WoW have 3 different talent trees (or "specs") that allow for further specialization of a character, allowing a lot of these mixes to be possible.

So here we go. (Disclaimer: no, I haven't played them all, but I know enough to talk about them, k? Just read. lol.)

The Paladin
A Warrior/Priest cross dealing super holy damage, Pallys can do their duty holding monster aggro as the tank, or heal relatively well when you don't have a priest. As the infamous self-healing tank, however, they are best at doing just that. This probably makes them an ultimate soloing class—all the melee you need PLUS the healing! I know from experience that this little quirk makes them particularly annoying in PvP. -.-; They can spec to be best at tanking, healing, or just general damage-dealing (melee and holy... which can be kinda be called elemental magic like a Mage!)
Some uniquities of the Paladin is the use of Auras, Blessings, Seals, and Hands; all various buffs applicable to the Pally himself, his party members, or any random shmoe he feels like buffing at the moment.

The Warlock
In my opinion, the Warlock combines the elemental magic of a Mage, and the comandable pet element of a Hunter (as they're the ones who tame and use pets in WoW). Warlocks deal shadow and fire damage, then summon demons to their side and to do their bidding. So like Hunters who send in their pets to tank while they fire away with bows and muskets; Locks use their demons to add to their damage-dealing in various ways while they cast searing fire and horrible afflictions. They can choose from an arsenal of 4 basic and 3 special demons with different dealing abilities; ranging from a small casting imp to a powerhouse, axe-wielding armored minion.
The Warlock can spec for more elemental damage [Mage], more effectiveness with their demons [Hunter], or—unique to this class—to deal damage by DEbuffing and damage-over-time effects (you can run, but you'll still die by magic!).

The Shaman
A healing, elemental magic dealer with melee and limited tanking capabilities, the Shammy is quite a mix. This Priest/Mage/Warrior cross is one of the handiest to have in your party, tho, as they are able to fill any needed role to an acceptable level without even having to specifically spec for it. Their range of even non-specialized abilities make them effective while soloing, but their signature abilities greatly benefit parties and raids. Shaman are masters of the elements and are known for their totems; one associated with each element—earth, fire, air, and water. (sorry, no heart. D: ) These totems do a number of things; from buffing the shaman and/or party members, debuffing or attacking monsters, taunting enemies and grounding their magic... to one that's pretty much a bomb. They can spec to be a Mage-like caster, a Warrior-like melee dealer/tank, or Priestly healer.

The Druid
Ah, the jack-of-all-trades Druid. My personal favorite, as this the most hybrid class I've ever had the fortune to play!! *loves* (ahem...) Bias aside, they are truly unique in being able to do... pretty much anything to some degree. The Druid's highly unique quirk is that their affinity with nature allows them the power to shapeshift into various animal forms to harness their abilities. There are 4 combat-oriented forms and 3 "utility" forms... no cool powers, but quite useful.
Bear: A tanking form. Armor, stamina, and endurance are increased like, 300% at high levels, and abilities become very Warrior-like—crowd control, aggro management, taunts, and stuns.
Cat: This form grants Rogue abilities like combo attacks, speed and agility, and (any Rogue's favorite) a stealth state that allowing limited invisibility and bonus attacks.
Owlkin: an antlered owl-bear looking creature from Warcraft lore, this is a souped-up caster form-- an armored Mage. Mana and HP are super boosted for dealing deadly magic but lasting longer than a fragile normal caster.
Tree-of-Life: um... a Ent-looking... walking tree. lol. Priestly healer form, offering powerful heals and uniquely potent group heals.
The 3 utility forms are Sea Lon, Cheetah, and Storm Crow, allowing improved swimming, fast ground movement, and flight, respectively. (which is a whole other barrel of fun!)
Druids can spec for melee and tanking (enhanced cat/bear), magic damage (owlkin), or healing (tree), but not all three. And of course... being jack-of-all-trades does mean master of none. Druids are effective in any position if you're lacking, but nowhere close to their pure counterparts.

The Death Knight
Quite possibly the hardest hybrid to figure out due to his range and type of abilities, the DK is also named WoW's most overpowered class. A force to be reckoned with against enemy units in the original Warcrafts, this new Hero class of undead dark knights are necromancers, summoners, and masters of blood and frost (so not fair!) They ride around on demon horses in dark armor dealing massive melee damage with not magic... but Runic power. Runic power is generated by using various magic abilities of 3 elements: Blood, Frost, or Unholy. Generating enough Runic power then unlocks greater abilities (melee OR magical). Within these 3 elements come abilities that include grabs, immobilization, damage-over-time effects, stuns, power hits, and summons. Speaking of summoning, a DK may summon various undead and unholy creatures to do their bidding... mainly zombie-ghouls and gargoyles. Ya dead? not for long! Death Knights can raise a fallen player as their undead slave for a short time (I've been enslaved before... it's crazy D:)
Any of the 3 specs for a DK allow for tanking and melee, the only differences are things they can summon and what kind of magic they deal. So there you go; some kind of Warrior... Mage... Warlock... mixed up damage dealer.

Okay! wow. There you have it, the more interesting class choices of World of Warcraft. Not to say that the traditional ones aren't interesting... played well they are amazingly effective and fun-- in fact they'll often get you picked first for groups ("Need tank and healer! PST plz") But no one can argue the handiness of someone who can fill multiple roles at once!